I intend to go there soon and buy a 10 year and 1.6 engine car.
hahahahahahahahahahahahahaha
sorry it's because of all the Jimmy Savile jokes that have been flying around......
Regarding buying the car you will have German plates and you have to go to the correct registration office in Poland Urzad Celny, pay money, 7% or so of the value of the car. Therefore is for example you pay 1000 Euro and pay 7% off that to the Urzad Celny. Now if for example the seller were to write a receipt for X whilst the true cost was higher at Y you would pay less registration fee. Obviously this is illegal, as obvious it would me exchanging money off the books and writing a false receipt, which means criminal collusion as it would benefit both parties for tax and import reasons, so very naughty. ;)