Our previous 2013 Heartland Trail Runner had the slide-out rear bumper-bike rack.
While it was a cool idea in theory . . . it was a major PITA to use.
So much so that we skipped it as an add-on accessory for our Prowler.
We found that we never took the bikes off of the rack as it was such a hassle to put them back on and strap them down when it was time to roll!
Notice the common theme with the bikes . . . trailer in the campground . . . bikes still on the rear bumper rack?
Plus, go down a dirt road and those bikes get filthy (found that rinsing off the bikes was the only real good reason to have the outside shower).
That rear bumper rack did come in handy when I bought new wheels and tires for the Trail Runner to replace the BlowMaxes . . .
A flip-down rear bumper rack was an optional accessory that we really considered . . . but passed on when we bought our 2015 Heartland Prowler.
Right now we don't carry our bikes with us . . . still looking for a solution!