car loan / ppi query

Had a call from one of these claims companys last week which set my mind thinking,  bought a car in 2002 from a local dealership but have no paperwork now relating back to it, so no account numbers or anything. Also I've changed banks so unable to access details via them. Found an old bank statement from 2007 showing  monthly payment to First National Motors so  must have taken the loan out over a 5 year term.
I'd like to find out if there was any PPI or similar on the account & then check out if it was mis-sold to me but not sure where to start.
Have read numerous web postings about people being told they can't get copies of agreements going that far back or that the complaint would be with the car dealer & not the finance company so any help/advice/pointers would be appreciated.
Thanks in advance.