I'm watching NASCAR for first time in years (don't judge me) and want to know why does all the cars look alike?

May be...

NASCAR got tired of the whining..
So they made them all alike..

Only the grill and paint look differant as far as I can see.

Because that's how it is.

The bodies are different but only slightly. Light decals, grills, bumpers, body lines etc.

They did it to make the competition closer.
The Front clips are slightly different

They try to keep it as even as possible so they make them build them pretty close to the same so one make car doesn't have an advantange over the other cars. It still happens anyway but NASCAR tries anyway.property listing in california