to be honest with you, they are claiming to e a correct stock boxster offset, and were all surprised that they didn't fit. on the back it just says Made in Germany, German design and some other numbers, and for offset it just says ET---- lol
i mean it was really weird, before i even moved the wheel close to the hub it was already hitting the shock, wayyy off.
front ones fit just fine, no problems.
im going with 225/40/18 front and 275/40/18 rear, i got Kumho ASX. my GFs brother runs them on his mustang and he loves them, he works at a tire shop and can get pretty much any tire, but he stuck with these for a 3rd or 4th time, so i said what the hell...he runs 295s on 19in Saleen wheels