Go to
www.wheelcollision.com and get to the Cadillac wheels list, then to whatever model wheels you want. Find the little pic and click on it for a larger view. With a bit of creative Photoshopping you can put whatever wheels you want on
your car's side view.
Just remember to keep bolt circle, stud count (5 or 6 ?), stud size (yours is 12x1.5), offset, and outside tire diameter the same as stock: that way, going from a 15 or 16 to a 17 or 18 will make no difference in handling. Rim width should be close to your OEM: if your wheel had a rim width of 7.5", don't go more than an inch wider - fenderwell rubbing in turns.
...............I see 7-spokes, but not 6-spokes.