Any problems running a little wider tire on the rear stock 18" rims?

hey bro.. i did it.. they fit fine but there is too much sidewall.. it doesnt look good at all.. go with 255 40 18's they look really nice and the stance is a little better than with the 255 45.. the taller tires in the back dont fit the rest of the car...

thanks for the info, i was just asking because i need some new rears and there are some for sale in that size on ebay with pretty good tread left for a good price.