Is it possible?
 

Is it possible to widen the rear end without spacers or different rims? Theres no reason I ask, I'm just curious if anyone who's anything. Maybe some sort of swap or conversion?

I doubt without some serious custom fab work.

Sure, cut the car in half and weld in a few extra inches down the middle.

Joking aside theres not an easy way to do what you're asking without touching the wheels. You can't move the whole suspension further out as the top bolts into a specific pad formed in the sheet metal. You could probably have some kind of custom extended hubs made, but thats doing the same thing as a wheel spacer but with insane cost.

You can change struts to an FE4 suspension and run 225/55R/17. With a FWD car I doubt you need any more than that.