If you don't finance the car, most dealers on out of state transactions give you the option of paying the dealer the appropriate California taxes or not. I always choose to pay the taxes directly to the state at the time I show up at DMV to get the car titled and registered. Also, if you paid cash you should have gotten the vehicle MSO ("birth certificate" / title) when you took delivery - they got your cash but you didn't get any proof of ownership - never give up the cash without the MSO or other evidence of ownership. Brandywine's a big dealer and I bet they do a lot of out of state sales - they should be able to figure this out for you.