The offset is definately too low. for 16x7.5 you want an offset of 35mm for a perfect flush fit.
Check this site for a way to calculate it...
http://toy4two.home.mindspring.com/offset.html
It says that versus a 35mm offset, which sit flush with the body on my car, see my pics, that the 23mm will:
The clearance from stut housing to the inside of the wheel will be 12mm MORE
The outside edge of the wheel will EXTEND an extra 12mm
Alon