Can I put coilovers on my 2007 Pontiac G6 two-door coupe

Hello, you'll need to consult some kind of custom performance shop to determine what can be done. More realistic is that the offset of the chosen wheels is probably not appropriate, necessitating suspension modifications that are not cost effective or sensible. Definitely seek guidance from a local shop that can give you some hands on advice based on your specific circumstances, not my guessing without much knowledge of your car or parts.