Thanks to all who replied to my SUV/4wd rental question. Sounds like the best way to try to ensure you get a 4wd when you really need a 4wd is to make a reservation (the type with no penalty for cancelation) through multiple companies and hope that one has a 4wd when you show up at the counter.
Also, now that I know how cheap and easy it is to get chains on a rental vehicle in Tahoe area it reduces my angst over this question. The difference between a midsize car and 4wd/SUV can be as much as $750 a week. That pays for 10 sets of chains and crews to install them for you.
For Rickg in case you change your mind about shuttle: besides trying various travel websites (expedia, kayak, rentalcars, etc.), also try getting a promo number from a site like rentalcarmomma and plug it in websites for discount. And I agree with Shred, you don't need 4wd to travel I70 unless you get real lucky.
Expedia yielded $351 for fullsize car, Mar 4-9, thru Payless. Oops, nevermind on last, just realized Rick needs to transport six, not likely with gear in a fullsize.