Google won't even run car data ads on anything that mentions hpi.......
This is heavily TM'd however you can fight them on it. They came after me for hipclear.co.uk and .com years ago. I told them fine go to DRS or court etc, but I'll challenge their tm on grounds of that it is now a generic term. They declined to take it any further.
If you spent 5k on the name, then 5k overturning their TM which is highly probable in my opinion then this name now becomes a 100K name.
Trouble is that there are only two players in the car data market that offer full checks, those two are Experian and Equifax. They have different brands but 95% goes back to those two and they won't rock the boat for each other, nice little cartel they have there.