Originally Posted by perry05G35

I am pretty sure you meant to say the offset in the front is 35 not 45 and the offset in the rear is 45 not 35. They will definitely fit on the IS300 they MAY NOT line up with the fenders like they do on the G35 though because I don't know the factory offset for the IS300. Look on clublexus.com they should have some staggard IS300s on there with the offset.