Man, this sucks. It'll be cool to spend a week in SF but I'm going to miss my stook so much! I'd love to rent a stook for the week, but it would be about a grand - I can think of much better things to spend that on. It looks like I can get a convertable Mustang for about $200 for the week. It'll be an automatic and the V6, but it's better than, say, a Malibu or Escort.

 

There are lots of Miata rentals out there. I rent one every year. Little more than the Mustang probably but a good substitute for the stook.

 

$1025 for a week at Specialty for an S2000.
$330 for a Miata.
$450 for an MR2 Spider.

Specialty Car Rentals of San Francisco

if you're just driving around the city it won't really matter WHAT you have. but if you're going to have a chance to spend ANY time driving out of the city i'd suggest picking up one of these.

perhaps they'll give you a deal where you rent the miata for 6 days and the S2000 for one for a compromise rate?

 

There is a company in SF called RENT CHEAP which kicks ass (not as good as RENT-A-WRECK in LA, though, where I got a beige '73 Buick Le sabre), they get you 80's Hyundais, each one of them with a problem (like the driver's door not opening from outside...), and I say 'each one' because in 2 weeks we had to change 4 times of car after they all broke down!
But then again, this is the USA, where 'you are what you drive', and most Americans would never be seen in a "crappy" vehicle, so our feeling of ultimate coolness was not really understood by the people we met...