Rear brake master cylinder failure (recall 15V-142)
Recall 15V-142 covers 2015 Scouts: a defective rear brake master cylinder can cause reduced or total loss of rear braking. The fix is free at Indian dealers — run the VIN and confirm it is closed. On inspection, the rear pedal should feel firm with no sponginess or fluid seepage at the reservoir.
Ask for repair records covering this item. If it hasn't been addressed and the car is in or near the mileage window, price the up to $400 repair into your offer — or make it the seller's problem.