No. Two totally different cars.
17"
Yes
YES you can fit 20's on a 2003 cavalier. The rim can be as wide as 8.5 inches and the tire size must be 225/30r20. The lug offset for the rim must be 5-100. The reason why I know this is because I have a 2003 cavalier on 20s
No, not without adaptors.
16x6
16"
Will as 20 inch after market rim that's on a Chevy fit my Titan
You can go uop to 2o"
No they will not fit a cobalt ss. Cobalt ss is 5 X 110. This makes it very difficult to find aftermarket wheels! Check tire rack! Sorry!
no
No.
16" x 6", 4 Lug, 100mm Bolt Pattern