Hi-
the stock 17 wheels and tires on my 2004 c70 convertible are beating us up on the horrible streets of New Orleans. So looking for 15" inch wheels. I believe that any of the volvo 15 x 6.5 wheels with 5 x 108 lug pattern and 43mm offset will fit, but if you know better let me know too!
thanks

 

check your brake rotor size. The 15s won't fit with all rotor sizes. You may need to down size to 16...

 

15 inch wheels will fit on a C70 but it will ride worse. C70s never came in 15 inch wheel and for good reason. 16 inch wheels is a good comprise. Do you have a picture of the 17 inch wheels that you have?