Ive just just some 16/205 45 on my car, and they fit perfectly with plenty of space round so there is no rubbing.
The wheels have an offset of ET 42 and after adding the 15mm spacers I had from my previous wheels makes it have an offset of ET 27, which is nowhere near the recommended offset of ET 15-18.
Although the wheels do not rub, is there any other reason why i shouldn't have it at this offset?