What sort of person has a fairly new car with 4 different makes of tyres on it? I would not accept a car especially from a main dealer like that.It just says to me that the previous owner was struggling to run the car and what other servicing things were not done or half done on the cheap.You can get a fairly decent set of tyres these days for a reasonable amount of money if you shop around and a main dealer will have access to tyres at good prices so no excuse to have a car for sale with mis-matched tyres!