Hi, I was wondering what would I need in order for these rims to fit? They are front: 8.5"width +40 offset rear: 10"width +45 offset. What kind of spacers will I need, will I need to roll the fenders and extend the lugnuts? Is it worth it to work with this type of situation. I also have rotora BBK all around if that is a factor, and my car is pretty low, and kitted out. Thanks in advanced.

 

assuming you have a coupe, you'll need 25mm spacers front and rear, but even with 255/285 tires it wont be fully flush. Unless you're getting a really good deal on the wheels, i'd wait, save up your money, and get wheels with the right offset.
-GP-

 

+1. I got my wheels for a steal and the guy sent me some 40 offsets in the rear (19x10 +40). I had some help from redlude and now with 30mm spacers, it brought my overall offset to +10. I am happy with that. You will prob. have to use spacers anyways because of your bbk, i doubt those wheels are custom.

just do the math what ever spacer you get, subtract the offset of your wheel from that number.
so 45mm ofst and a 25mm spacer will only yield a 20mm offset so that should be sufficient if your looking for a flushed look.
What type of rims are they?

 

With those offsets/widths, I'd want to run 30mm spacers front & 35mm rear. That's not even super aggressive, either.