Hi, My AU II is on gas and is currently having a few problems with backfiring. After one backfire there was a bit of a noise and I discovered a part lying on the ground. It's a black plastic box about 200mm x 100mm x 100mm and it normally sits inside the front passenger side wheel well. It has a plastic tube which is attached to one end of the black box and the other end is open and comes out into the engine bay.

charcoal canister?

Haha, I believe thats the charcoal canister, supposedly it deals with petrol fumes and s**t, I believe it lives up in the wheel arch type area behind one of the black plastic splash shroud things, and that reminds me i need to replace mine to. hehe you may be lucky, and be able to just clip it back on but a good chance it's broken one of the clips off.

None the less don't fret to much as the car will run fine in the mean time, till you can sort it, as a mate said, it'll be right just maybe avoid any open fires,

thanks guys, I was a bit worried about driving it without it fitted but now I'm a bit relieved. I've got the car booked in for a bit of work in a couple of weeks so I'll get this replaced as well.
The work involves getting the car roadworthy, the roadworthy that the car came with when I bought it was bodgy. The gas tank was out of date and there was no gas computer fitted amongst other faults.