I have some Magnum 500 wheels 18x9 and 10s offsets are 36 in front and 45 in rear. no problems with rubbing or steering stops. I had 255/45's orignally on the front and nothing outside the fender. I am currently running 265/50's and they definitely fill the wheel well. As for the rear you should be fine with the 43, can't see 2mm making that much of a difference, if it does I believe you can get a spacer to make the difference up.
Here are some shots of the front with both the 255/45 (stock diameter tire) and the larger 265/50. car is lowered as well.
255/45's and 275/40 rear...

265/50 and 295/45 rear...

_________________
John
2007 Mustang GT w/a few mods...
