As I recall the standard 4 Seater dampers have an integral bump stop? Maybe one of the 4 Seater experts can confirm.
Yes, the original dampers on the later four-seaters have a long bump stop or spring assistor as MMC like to call them. I tried AVO's at the rear, but this did not solve my problem.
Only when I got air suspension dampers in
addition to the original ones, the car was able to handle four small adults plus luggage. Now I can pass speed bumps at the same speed as normal cars
Harald