Is the markup only happening in the USA and the UK where there are large number of buyers compared to number of cars.  I moved to Cyprus about 6 years ago, and had to sell my GT3 prior to moving cause the costs to import it were insane.  Prior to that I had an excellent relationship with my dealer in Lebanon as I've purchased over 10 cars from them including 4 GT models. Never once have I paid above MRSP in fact I even got a very small discount for being such a loyal customer even on the GT models (3 GT3's and 1 RS).  Actually I remember when I ordered the RS, and had my GT3, I was in the process of moving, I received multiple offers to buy my slot from 3rd party dealers, and out of respect I told my dealership (friends), and they told me that If don't want the car it has to go to the next person on their list without premium at MRSP, and if I sold the slot to a third party I would no longer be in their good graces.  I gave the slot up, was refunded and it went to the next guy on the list who I happened to know, again at MRSP.  There are some good and fair dealers out there, who still care about long term relationships and doing things correctly.  They are few, but they still exist. Till today every purchase made at that dealership I remember extremely well.

I've been porsche less since, and It was only until Feb I decided to try my luck with the local dealer for a GT3 allocation (first car I buy from them) and I landed a slot, again without paying anything over MRSP.  There were some silly shenanigans after I paid my 35% deposit, which were completely ludicrous and un professional, but it was all sorted out at the end (after some heated exchanges) and I expect the car next month. Those are just my experiences....