You haven't mentioned what country you're from in europe - they're all different. I doubt the dealer will do anything unless there's danger of them losing a sale. If you've already bought the car and the deal is over and you show up asking if they'll swap them, you'll be out of luck. If you're considering buying it (but haven't yet) then you can do what I did. Make the deal conditional upon them changing the wheels/tyres to what you want. I spotted another used 5er on the lot with the wheels I wanted so I said if you swap the wheels with that car over there, then we've got a deal. They did it.

 

Hi guys,

I was hoping you guys could help.

I have a 530d M sport (2006) with 18" Goodyear NCT5 run flat tyres on the rear that require changing very soon.
I tried putting on a set of Dunlop SP sport 9000 255/35-18 on the back and it upset the handling of the car, so i put the run flats from the front on to the rear and the dunlops on to the front and this was alot better.
So to recap i have on the front Dunlop sp sport 9000 255/35-18 and standard goodyear NCT5 (RF) 245/40-18 on the back.

My question is can anyone recommend tyres for the back of my 530d M sport which do not upset the car excellent handling?

Thanks in advance