My slider rolls back 11 inches.
I've never had to use it yet . . . the key work here is "had".
I tried it once at the dealership the day we picked up the Prowler, but I don't remember if the tailgate was up or down (I think it was up).
Next time I back our Prowler into our yard and our neighbor across the street has his truck parked right in my way (and he is not home) . . . I'm going to try the slider to see if that makes the back-in easier.
I do like having it . . . even if I don't use it!
Kinda' like having a tool in your tool box in case you need it.
I'd rather have it and not need it than to need it . . . and not have it!