does any one ever use the services like HPI etc to check a car before they buy one?

It really depends how much the car is going to cost? And if you can afford to loose £££.

Private sale I would check for sure.

I've not bought privately for a while, but I guess I would.

If you are buying a "decent" car privately it makes a lot of sense to do a HPI check..When I was in the trade I came accros a couple of people who had been stung,,just because you have the car,keys and V5 doesn't mean it is your car,as they found out,the finance company were very happy to get THERE cars back,,doesn't cost much and well worth it.
Mark