Small Rumble Suggestion? Extra turret damage with Overheat?

AP tops like Rumble have a slightly harder time last hitting and taking down turrets since their basic attacks don't scale with AP. They're also a rare breed. I think it'd be nice if Rumble, and maybe some other AP tops, could get some sort of bonus damage to turrets at the very least. Perhaps just by making his Overheat basic attacks deal more damage to turrets (since they don't work on turrets but work on every thing else). There are more than plenty of AD tops that can boost their attack speed or make their next basic attack deal bonus damage to turrets, so I feel this would help balance things out and get them to see more play especially since his turret damage is abysmal later in the game. There are quite a few AD characters that can melt turrets after killing an opponent and it'd be nice if Rumble could match that.

Just an observation I made after playing Gragas a few times. He feels like a nice modern AP bruiser champion and he has one spell that slightly helps him push turrets.