Scam.

Sure this thing might produce a couple of watts of power. And you might produce enough of it after few thousand years to recover the costs you sunk into this nonsense. The real value of this thing is in duping suckers to invest money into it.

This is basically the same idea as the question someone had a few weeks ago about charging EV batteries when they're cruising on the highway.

This is also close to a perpetual motion machine. The amount of energy you could ever get out of the vehicle's suspension when it moves is so miniscule it wouldn't be worth the expense. You're also just recovering part of the energy you lost, and it's energy that already came from the battery. To really recharge a battery, it needs to be charged by an external source of energy, these little gimmicky devices don't improve your range really at all. Bumps in the road are not major sources of energy loss in any vehicle, unless it's completely cratered.