Hi, My fuel gauge hasn't worked in about 4 years! I just fill up every 200 miles! I read that it is probably the fuel sender unit, tucked away behind the Off Side seat. So today I took a 'spare' out of the Green 1.9 Z3 that I bought to break and steal parts from, this gauge sender was one of the reasons why I ever bought the boston green car. Here goes - 1st - I removed the seat, not sure you have to, but a fair amount of petrol spilt when I took the unit out. 2 rear bolts and 2 front bolts, then undo the wiring clips, sorry no photos for this part. 2nd - cut the perforated notches in the panel of carpet behind the seat with a Stanley knife (other knives are available) 3rd - remove the 4 Phillips screws on the panel 4th - unclip the slider unit, pushes sideways first then away (bottom right in photo) 5th - remove the jubilee / metal cable tie style clips using a bit of brute force and a mixture of pillars and long nose pillars. 6th - remove the black screw top, using a flat screwdriver and persuader as required 7th - gently ease the sender unit out (it is delicate), I had to stop and put a plastic box under the car to catch seeping petrol and a rag to soak up the fuel in the car. 8th - done! If you're lucky I'll put an install gude in too, but I'm guessing it will be the same in reverse!