It is possible to get 15x8s or 16x8s on a narrow body car, but they're not going to be off the shelf fuchs. It's not well know that its possible. Basically, you take a pair 15x7s or 16x7s and weld an inch of back space on them. I know that Harvey Wiedman can make them because I have four. He makes them specifically for the narrow body cars. Depending on how low your going to make your car, you may have to roll the fenders. I think Clint Smith at Rebel Racing also makes a 8x17" wheel for a narrow body car. The attached link shows Clint's car, and I'm pretty sure those are 8" rims on the back. I think his fenders are rolled as well
http://rebelracingproducts.com/images/RebelRacing_006.jpg
Good luck!