My understanding regarding the plastic coolant pipes is that the question is not if they will fail but When they will fail. When it happens you could pretty much be stranded because you could lose all coolant quickly, that is why most will suggest that you upgrade them to avoid a situation like that they are awesome trucks, I love mine. Good luck!

 

My Cayenne has been extremely reliable, but I agree with past posts that 1,500 is a little expensive for the needed repairs. Honestly, you're probably going to have to just take a risk. The price is pretty good and it is from your brother but there is a chance you could have major expenses since that is, by my tastes anyway, pretty high mileage.