After a few years of use, the cabrio roof may begin to sag and not look as taught as it was when new. Although this is a problem more often found on the Roadster, this guide will take you through the retensioning exercise for the fortwo 451.
To access the tensioning points, the rear spoiler, which houses the high level brake light, needs to be removed. Keep the roof fully closed to begin with.
To remove the rear spoiler, start by removing the two TX10 screws which hold the high level brake light.
Disconnect the light from the wiring and remove the light assembly from the car.
In the locations shown, there are 4x TX30 screws which hold the rear spoiler to the car. You need to remove all of these.
Close up image showning the screw locations:
The spoiler will now be free but it is stuck with a tacky waterproofing seal at either end. Pull the spoiler firmly but carefully at either side and it will come away from the car.
Lift the weather seal up to reveal a metal strip which pins the horizontal section of roof in place.
This will reveal 10x TX30 screws which all need to be removed.
At either side, you will see the tensioning straps which will be tucked underneath the guide tubes. These are clamped by a metal bracket held in place by a TX30 screw. Slacken off the screw and pull the strap tight before retightening. Remember, you must ensure that the roof is fully closed first.
Check that the tenioning strip feels nice and taught.
Repeat for the other side and ensure that you tuck both straps away as shown.
Now that the tensioning straps have been retightened, the roof canvas will tighten up once you screw the metal strip back in place. to make this easier, open the roof slightly before refitting all the screws. Fold the weather strip back down as shown.
It is a good idea to test the operation of the roof before refitting the spoiler. Close the roof fully and keep an check that it closes fully. If the roof is over-tensioned, it will stop before it has fully engaged in the closed position. You will need to slacken the tensioning strips slightly in this case.
Once you are satisfied, refit the spoiler and brake light in the reverse of removal.