the front fenders are 4" wider than stock and the rear are 5" wider than stock, that's how the tires fit
The rims are 8x18 et 50 on the front and 10x18 et 40 for the rear.
The best fit I got under stock fenders was 205/40 17 on 7x17 et 55 turbo twists on my street bug. Fits perfect all the way around with 11mm spacers.
The sensor is for the abs pickup in the front spindle of a 968. I don't know if 944 turbos came with abs or not but there should be a boss for the sensor at a minimum. I'll try and get some pics tomorrow since I have to tighten mine now that I think about.
Oh.. and she runs, sounds mean as hell, and leaks a little oil here and there (gotta track those down tomorrow) video and more details forthcoming!