I have seen W126 SELs with Recaro seats front and rear (extremely rare). If you are asking about E500E cars, the seat bottoms may make rear placement/entry very tight due to the extended Recaro Ideal C seat base. The W124 is the mid size chassis and does not have the rear seat room that an S class LWB car has. Just my thoughts and $0.02. Even on the AMG W126 cars, the vast majority (99%+) have Recaros in the front only. Doesn't look odd to me, but I am biased....