I bought my R55 used so I've been learning about it as I go and at a meet up it was explained to me that the gas cap is supposed to lock. The actuator still works, but the previous owner cut off the piece that sticks into the cover to lock it.

Found a replacement actuator on eBay and I've tried to find the location twice with no luck. I went in through the rear with no luck, although I could follow the green pull cable. Next, I went in via the wheel well but again, no luck.

My next guess is to go in via the backseat but I thought I'd post here in case someone else has any suggestions.

 

Check realoem.com, you should be able to find a diagrm there that will point you in the right direction.

 

I looked all through my Bentley Manual and there is nothing about it. Odd

 

I've seen plenty of diagrams but it doesn't really help unfortunately.

http://www.realoem.com/bmw/enUS/show...35#51257174587

 

it's behind the panel in the trunk.

 

That was the first place I looked, but I couldn't find it. I thought I took a picture but I didn't. I'll take pictures next time I dig into it.

 

ECSTuning was 100% correct. I removed the driver's side rear panel and the actuator is mounted just above the wheel well.

 

Great you found it.