A little more in the way of amplification. Even with the delay, once the tranny locks up in reverse, it does not slip, shudder or misbehave in any way. If you increase the rpm's to about 1200 it will decrease the delay (raising line pressure.), but when you let it drop back to idle, it maintains engagement. I am not an expert on MBZ trannys by any stretch of the imagination, but my experience with GM, Ford and Chrysler tells me valve body is the culprit. A blown seal would always leak, but who knows..
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.