I keep a folding small step stool in my cargo area anyway for any "wealthy" old relatives
or to reach my roof while waxing or drying water with a microfiber.
I'm not a fan of running boards anyway especially my being in the northeast just another thing to catch snow and salt.
I think running boards on a trucky type vehicles like a 4 x 4 are a great idea, but the X5 is really not that high off the ground IMHO.
I do think those electric aftermarket retracting ones are cool from a video I saw being installed on youtube.