I really hated the stock Toyota rims, and had a really tough time finding a decent replacement. I ended up getting MOMO Winter II rims from Discount Tires ($90 ea), as the best choice (to me). These weigh about half the stock steel rims, are better balanced, and Momos…. What have you done?
Admittedly the weight statement was from the dealer - and I did ask twice, plus hefted each. The new ones do feel lighter (totally empirical).. These are the same size as stock 15" rims (did not want to risk the larger size), and here is a link, showing the rims on (my) a white Prius. (hope it works) See Wheels on Your Vehicle - Discount Tire
It would be great if you posted another pic from the side of your car...the web site is fudging the inches a bit...15's look like 17's to me. Thanks!