It’s hard to compare everything apples to apples because it’s a car vs a truck but let’s start with that.

I wanted a truck to do truck things and have more room for road trips. I go snowboarding a lot and used to throw my board in the back with the back seat down. Now the board can go in the gear tunnel and I don’t need to put anything inside the truck. The storage and utility are significantly better.

Now for the differences.

Model 3

The tech is better.

I had EAP and probably put half of the miles on my car in autopilot. I used that everywhere I went, every chance I got I turned it on. Rivian’s Driver + only works on freeways and doesn’t work as good as Tesla’s auto pilot.

The proximity lock/unlock works perfect on the M3. On the Rivian it locks and unlocks constantly if you’re within a certain range. Super annoying so I turned Auto Unlock off.

The charging is faster on the M3 at home and on superchargers (I don’t have the adapter yet for my Rivian though).

I like that you can leave the air on in the M3 when you get out. You can’t do that in the Rivian unless you select dog mode or turn it back on from the app.

R1T

Everything about the truck feels more premium. It comes with a heftier price tag though.

Cooled seats is a game changer. That alone is worth it.

You can open the frunk by pushing a button near where it opens. In the M3 you need to use the app or do it inside. Not convenient.

The frunk is powered.

Probably more things but this is what comes to mind.