Ahh, makes sense. In Colorado we pull the plates and keep them; they never (should) go with the car. Seller can be liable if the new owner doesn't transfer the registration and title.
The other thing that a lot of buyers here don't generally know is that the seller is required to have an emissions test passed within the 30 days prior to the sale. Otherwise the buyer accepts responsibility for it passing emissions, which could be a problem (and maybe the reason for the sale). Dealers can try to give the buyer a $25 coupon to the seller, to cover the emissions test cost, but the buyer can insist on the dealer having it done within 3 days after the sale. After that it's on the buyer.
The other thing that a lot of buyers here don't generally know is that the seller is required to have an emissions test passed within the 30 days prior to the sale. Otherwise the buyer accepts responsibility for it passing emissions, which could be a problem (and maybe the reason for the sale). Dealers can try to give the buyer a $25 coupon to the seller, to cover the emissions test cost, but the buyer can insist on the dealer having it done within 3 days after the sale. After that it's on the buyer.