I wouldn't change the wheels I think they look spot on, maybe have them done a different colour I'm not sure on the stripes I quite like how it looks without them but that's just my opinion:)
If you value a comfortable drive then keep the 17's, if it's looks then 18's all the way, but, you'll have to lower to make them look right
I was gonna do matt black stripes on my car, looked good laying the vinyl on the car but, not done it yet
I suppose it depends on which 18" rims yer after for the looks side of thing!!!!!!!
good shout with colour change though... Stealth..? Window tints?
As Eddie says just change the colour. Should get it de-chromed too
All depends on why you are looking at 18's ,nothing wrong with 17's or do you just want a different type of wheel and if so ..OEM or after market or copies of OEM are never just right (IMHO)
The cars in front are New MINI Scotland