Check out MitziKitty's HHR on here. She runs Vintiques and wide whites. Awesome combo and a nicer ride. I think they look badasss on our cars.

 

I am not saying that this applies to you, but alot of times new shocks and struts do alot more for the ride quality than that of new tires and wheels. Firstly the present tires and wheels would have to be a real issue before they can render a ride that is so bad that one want to take them off. I would be curious to know what tire and rim size that you are using right now. (Brand and size)

 

He hasnt brought them yet but he swears he had the on his wife's car. Maybe he fudged a little.

 

Maybe, even if they dont fit, 15" rims are relatively cheap compared to 18" rims. you would still want to go with the rim width between 6"-7.5" and the 215/60-15 tire. 8-D

Also you might want to get your shocks shocks and struts checked out like hraleysshhr mentioned. You might also find some that have more dampening to them. It would create more noticable body roll, but the ride would be alot softer. Maybe a set of Monroe Sensa-Trac Struts and Shocks would be up your ally.