will these calipers fit inside 15" rims?

They should fit, i have a set that i will be putting on my bug, i know that they fit 16's easy as i have some boxster wheels and the clearance is over an inch on these.

What wheels are you running Pete? There can be problems with 15' Fuchs

Steve

I ran 15x6" fuchs rims on my 944 turbo front brakes for a while before upgrading to 17's. It requires 15mm wheel spacers to allow the wheel to clear the calipers. Also you need a front thats been narrowed to keep the rims under the guards.