This may be a dumb question, but how sturdy is the rear bumper? I snowboard with my buddies a lot and usually gear up at the rear of the car. Since the rear bumper is plastic, will it be strong enough to support 2-3 people sitting on it?

 

huh?
first of all you wont be able to fit three across. Also, try it out on your own and you will realize that you don't sit on the bumper, but rather in the trunk.
I would spend a couple of bucks on something to protect the bumper (rear bumper applique).
I have used my truck to get geared up for biking, I helped.

 

Not really worrying about scratches but it falling off or cracking. Especially when putting on boots and using the edge of the bumper to sit or rest their cheeks on.

 

sitting on a bumper? LOL. i recommend the roof.