Good fun... but be aware... you will not have enough time to complete the track in the San Francisco traffic and will get charged extra for going over allocated time!
The Sat Nav on these things is next to useless - voice guidance only, no visuals. If you know where you are going, great, but if you make an in-correct turning then Sat Nav goes silent and does not pick up where you are quick enough, so your left all on your own with a paper map which is provided. Not helpful, especially if this is your first time to the USA and driving around in this country.
A good hint is wait until someone else who knows the route gets going in their car and follow them!
Paid for 2 person but only one of us get to drive. Both of us were in the same car. Should have purchase for 1person. Felt cheated...