I see what you're saying but it is the dealer that owes the tax not the purchaser. The dealer simply charges you for it and breaks it out so people can see tax, title etc but it's all listed under the same purchase agreement. The way I understand it is, If an Ohio resident purchases a motor vehicle from an Ohio motor vehicle dealer and takes possession of the vehicle in Ohio, the dealer must collect sales tax and remit it to the Clerk of Courts at the time the dealer obtains the title for the vehicle. The Ohio sales tax must be paid based upon the purchaser’s county of residence. In a private party sale I have to pay the sales tax when I go to transfer title. Since the dealer actually purchased the vehicle and then sold it, they owe sales tax on it to transfer the title.
Dealers aren't required to obtain a title within 30 days of buying a vehicle like we are, They only have to obtain and assign title to the lender or purchaser once the vehicle is purchased by the end consumer, at that time they are required to pay sales tax on the sale in order to transfer title. This is why when you buy a vehicle the title chain isn't (previous owner / dealer / you). It just shows (previous owner / you.)