There has been a sob story told by the dealers lately that they don't make much money on new vehicle sales. The story is that the internet has put a bright light on the actual cost the dealers pay for the cars so they are having a difficult time making the huge profits that they used to make. The shortages we have seen this year do add some legitimacy to the rumor though.
I do know for a fact that when my Dad sold cars, the parts and service departments were where the majority of the money was made. They carried all the overhead for the dealership and the sales department was there almost as a gateway to sell those parts and services.
I remember those b u l l s h i t market adjustments being tacked on the 2008 Challengers. They were great cars but within a few years, the cars were selling for well below MSRP. For the dudes that HAD to have the newest thing, they sure paid a steep price for it.