Using the temp tag will work, but you are supposed to wait for your permanent plates before submitting the application (took less than 3 weeks for my plates to arrive). You will eventually get a Clear Air Vehicle certificate that includes your license plate number, VIN, and decal number (it is printed on the decals) which you keep in the vehicle with the vehicle registration. If you were involved in an HOV related stop, the officer could see that your plate matches the numbers on the decals and you are legit. The VIN will match too. I have not been pulled over in some time, but think cops deal with plate numbers, not VINs. The question is how you are dealt with if your plates and certificate don't match, even though the VIN does. Likely nothing will, but others have been know to be penalized for not having all the stickers so discrepancies in the paperwork could also lead to a ticket.