Car rentals in most cities are $60, $70 and even $80 per day. Sometimes even $100. Good luck finding anything cheaper. BTW, if you want to go to Tahoe, frequently chains are required (and cost extra). Do yourself a favor and enjoy the no snow winters of SF. Inside SF, no car is needed especially if you are on vacation.
Not going to happen during the holidays in San Francisco,or any other time.Sorry.
It will only go up the closer to the date you get. $35 is actually a pretty good deal for a holiday daily rate.
Try hotwire.com