Documentation is going to be 55 in cali.
The tax is applied onto the destination fee as well. Rebates come after the final price so they dont help with tax.
Visit truecar.com and ask the dealer for the invoice.
Figure out what you are willing to pay and use california dmv website to figure out what TTL will be on that price. That way you now the final price is something that lines up with a legitamate number for the car.
Buy at dealer invoice and don't accept any fees beyond the 55 doc. You can talk to the internet sales manager at a few dealerships, find one who is upfront about dealer invoice (Read: he sends the invoice to you for your understanding). If there is an advertising assessment fee in dealer invoice price that is something you can touch on, that may or may not be on table for negotiation, $300 is ok i'd balk at anything ~$600.
Of course everything else lines up as well, if financing get it done prior to entering dealerships when ready to buy. Know kbb for your trade in and get that after you settle on paying invoice for the car.
Tell the sales/finance manager exactly what you want and leave as soon as they get balsy with the numbers. If you get into negotiations (i'd reccomend avoiding negotiating, know what the car is worth, say want you want it for, and if they come back with anything else, leave) then get a breakdown of what is going into each number they show you.
Cliffs: 1) Know what the vehicle is worth before going into a dealership. 2) Buy car at that price (within ~500 of that price if you really love the car) 3) Have fun and look at lots of cars.