I have been looking at tires for 18/19 setups and am dying to get the Michelin PSS which is available in 205/40/18 which is just about the same as your 20/45/17. I think that the .4" addition to the overall height will probably rub the fins for the ac shroud but not much else. I am thinking this may be the way to go considering the PSS looks like it runs wide compared to other tires by looking at its section width (I would be mounting on 18x8 which is the max approved). I hate stretched tires and I want a bead protector which many tires do not offer but the PSS does have. The PSS is also lighter than most, comes with a mileage warranty (LOL), and is basically the best tire available. What do you guys think- is it worth the trade off even though it would create a huge stagger (205/275 front/rear)? There is also 205/265 available to reduce that stagger, which is the same stagger I use now. 17" wheels are out of the question because my BBK is huge so I am stuck with 18" front tires as my limiting criteria.