Remove and reinstall the rear deck so you can change your rear suspension:
Background – my car has the fold-down rear seats, rear airbags (SRS) and the rear sunshade. If your car is equipped differently, your experience may differ.
The interior fittings are all very well designed and made. In my car, everything fit well and nothing had to be forced or bent. The job has been described by others as easy but tedious, and I agree, with emphasis on the easy part.
Just to set the stage, I thought I’d describe the logic of the job: What has to be done so you can remove the rear deck to expose the top of the rear shock mounts?
- You have to remove the rear seat base to expose the screws that allow you to remove the rear seat side bolsters
- You have to remove the side bolsters so you can remove both the c-pillar trim and the actual deck itself (BMW M5 Tuning)
- You have to remove everything that actually goes through the deck and stops it from moving: the headrest posts, the child-restraint bolts and the air vents under the rear window so that it will come out
- You have to remove the c-pillar lights to remove the c-pillar trim, which in turn holds the deck in place at the edges
- You have to remove the three nuts in the trunk that hold the sunshade in place
- You have to pull the six drive pin clips that hold the front of the deck in place behind the rear seatbacks. The trim piece has to come off as well.
- Once you have the deck out, you have to remove the two interior speakers to gain access to the top of the shock towers.
A couple of notes – I did the work in an order that made it easiest for me to do, not the order that usually appears in instructions. I wore nitrile gloves to keep the back window clean. When I refer to “up”, “forward”, “down”, and so on, I mean in relation to the car when you’re outside it and looking at it.
bmw m5 tuning says that you have to Start by removing the headrests and their posts. The headrest and the posts are all individual pieces intended to separate. The posts are held in place by spring clips that clip into slots down inside the deck. To remove, pull up on the headrest itself until it comes off the posts. Then pull the posts out one by one. I’ve read descriptions suggesting they are hard to remove, but mine weren’t.
Second, use a small slotted screwdriver to pop the plastic covers off the tops of the child-restraint bolts and remove the bolts and their rubber spacers. The triangular trim pieces just lift out without any drama. You don’t have to actually remove the trim, but the holes make a dandy way to hang onto the deck when the time comes to remove it. (BMW M5 Tuning)
Next, get two small slotted screwdrivers and reach to the back of the deck and pry up the front edge of the vent cover. Each vent has four clips across the front edge and I just pried up with one screwdriver to create a gap, put the second one in and then just edged them along; as I did the clips popped one by one. Once the front edge is released lift it clear of the front edge of the hole then pull it straight forward to release the two longish (about an inch) rearward-facing rectangular pins under the deck at the rear. Don’t pull up, pull forward or you’ll break the pins off. These large pins lock the rear of the deck in place.
The last part of releasing the deck restraints is to open the trunk and remove the three nuts that hold the roller blind down. They’re pretty easy to spot underneath the deck in the spaces between the M-Audio speakers and they just unscrew.
Although it’s “out of order” the next job is to remove the lights from the c-pillar trim. The lights have metal spring clips at the top and plastic hooks at the bottom, so pry down gently at the top and they just tip into your hands and lift right out. (BMW M5 Tuning)
Removing the light exposes two 8mm screw heads. Remove them. For the moment, you’re done – we’ll come back to the c-pillar trim in a little while.
The next job is to remove the rear seat. Your workplace is about to become rather less comfy.
Run the front seats forward to make room, and then reach in and pull up sharply at the front edge of the rear seat once on each side. It will pop off the two spring clips that hold it in place. Pop each side in turn and then just lift the seat bottom out. BEFORE YOU FOLD THE SEAT BACKS FORWARD PUT IN SOME PROTECTION FOR THEM! I put a length of two-by-four in between the two exposed spring clips and laid bubble wrap on it so that the rear seat leather didn’t run into the spring clip. Once you’ve made sure that they won’t be damaged, fold the seat backs forward. You will have to sit on them, so make sure they’re well protected. (
bmw m5 tuning)
Next, remove the rear seat side bolsters. Reach down the front of the bolster and feel along the bottom toward the door to locate and remove the 10mm screw the holds the bolster in place. The screw is cross-ways in the car and goes into the inside of the rocker panel (not literally, but you get the idea). Once the screw is out, the seat bolster is held in place by two more clips. Near the top it’s held by a single spring clip similar to the ones that hold the rear seat base down. At the bottom the bolster has a metal tongue that goes downward into a slot. To remove the bolster the rest of the way, pull the top straight away from its mounting face about six inches down from the top to pop the spring clip loose. Once the top is free, lift the bolster straight up to get the tongue out of its slot and it’s out. Remove both sides. (BMW M5 Tuning)
Now that the bolsters are out, you are nearly done.
Now finish taking the c-pillar trim out. Since the screws are already out, the trim is only held in place by two plastic pins at the front and a row of tabs that fit into slots at the rear. The plastic pins stick straight out of the back of the trim piece, and if you break them, they can be replaced. One is visible and reachable at the top near the middle of the light opening and the other is about half-way between the front tip of the light opening and the front tip of the trim piece where it goes forward over the door. Hold the trim near the pins and give a firm tug straight out (90 degrees from the surface). Don’t pull too far! That will pull these pins out of their plastic sockets in the bodywork. Once the pins are free, pull the trim piece forward and tip it inward and it’s out. Remove both sides. (BMW M5 Tuning)
Next, take a pair of diagonal cutters and coax the center pins out of the six pushpins that hold the trim piece over the top of the trunk opening. The trim piece has five tabs that hook underneath the bottom edge and go up inside the trunk. Once the pushpins are out you have to carefully work the panel to release the hooks and get it free. Once the trim panel is off, you’re ready to remove the deck.
Getting the actual deck out isn’t hard, but it does take some heaving. Sit on the back seat with your feet in the trunk, grab the deck through the holes left by the child-restraint trim and then pull it up and towards you. Just keep working it and eventually it will pop out and pretty much land in your lap. Before you go all the way to laying it on the back seat, find the wire for the electric roller blind and unhook it from the right-most hold-down clip it so it doesn’t get stretched or damaged.
If you’re just doing suspension or sound system work then you don’t actually want to take the deck completely out. Roll it forward and lay it upside-down on the back seat. It will be held in place by the seatbelts that still go through it, and you can do all your suspension work with it in this position. The last step before the suspension work begins is to unscrew the two speakers at the left and right sides of the rear shelf. They are held in place with two tapping screws at the front, and they just lift up and pull forward. Unplug and remove them. The top of the rear shock is under the foam blanket in a hollow just behind the rear seatback and just inboard of the outer seat-belt reel. Fold the outside forward corner of the foam blanket back and look underneath – you’ve arrived! (BMW M5 Tuning)
Reinstallation is literally the reverse of removal.
I think the 80,000 or 90,000 Euro Quote that was given, includes the full G power package for the M5 like wheels, body kit, interior, wheels, and exhaust etc. I think this engine conversion is still more expensive than the dinan one. But the gains are different! if it was me i would go with the ASA/G Power kit. However, Since Stage two involves beefing up the engine internals, lowering compression, etc....I am surprised they are not offering a twin turbo conversion.... Supercharging is great, but twin turbos make the real power. Instead of 730hp, why not 800 or 900hp?? The M5 chassis is bulit like a tank and could handle the power upgrade better than any AMG benz including the SL65, CL65 series.
Base Actual Price: 2008 BMW M5 by G-Power - 240,000 €
