[ppbon]

... an "S".
But do invest in a PPI.
It will be the best money you spend on that car.
A good PPI will give you enough information to make a smart decision about the purchase.
It should also tell you what the market value for that particular car in that market should be.
I know, that's what I do for a living (PPI).
Good luck.
Happy Boxstering,
Pedro