New Tires- rears stick out more than original

[haleakalag]

Hi All- Have a 2009 G37 base convertible. Just got new Michelin tires at Costco. They are stock original 18 inch wheels and standard size tires, front 225/50/r18, rear 245/45/r18. The rear tires seem to stick out more than the front now, and it feels like there is a circular ridge around the central side of each tire. The car drives great, the sizes are correct, I'm just wondering if there is any way they could have reversed the wheels somehow (front and back) to account for the odd look and feel of the rear tires. The front tires are normal with no ridge. I hope I have explained this okay, its hard to describe. Thanks much.