WOW...the ancient blue and yellow Cali plate! (another thread "I'm so old I remember when.) mentions that plate!
Your offer is great.
I've done ride shares most every year for 14 years, and have a tip.
All of those rideshares except one were with only one burner.
Those "singles" were all fine, probably as I figured out how to make it the most painless for me.
Where did the pain originate?
Picking up multiple burners at THEIR location.
I suggest you insist
they come to your location with all their stuff.
A brief list of what can go wrong should you pick them up:
---you can't find their place
---they could be far enough off your route to eat up time behind the wheel. You DO NOT want more time behind the wheel, as you may be the only driver.
---you will find them in a home where "Oh, I need this" will happen over and over.
---they will have too much stuff. If they can't fit their stuff into their, or a friends, small car, they have too much stuff.
---you will be much later than your agreed on time for picking them up (from reading eplaya for years, it is clear that almost no one departs their driveway when they planned)
---they won't be ready when you arrive
---one of their party won't be there, but "they are on their way"
---they will kindly offer to pack their stuff in your "bus" but will do so with no "packing sense" except to keep things they think they will need in some non-efficient location.
---they will be packing drugs and claim not to have any. Dogs might sniff 'em out and let's just say, your burn won't be the same.
Put a notice in the Rideshare section: http://rideshare.burningman.com/
Insist they must get it together to bring them and their stuff to you.
State that you will have space for normal burner needs: water/bike/small cooler/food/backpack/tent, but not supplies for a Theme Camp.
You might want to consider strapping the bikes to the roof or some rack on the back of the "bus", but make sure your taillights and license plate are not obstructed. (such an easy ticket for LEO to write, and gives them an op to ask you if they can search the vehicle.