2001 RS weighs 50 lbs more with 4eat, L weighs 70 lbs more.
Total weight? Dunno. I'd guess it's a buck fifty or two, but that's a complete guess. Would it fit in the trunk? Most likely it would, but if you're getting one from a junkyard (or otherwise used) it'll leak crap all over the trunk. You're better off going to U-Haul or Budget and renting a pickup for $20. Plus it would probably break your spare tire cover.