Continuing on this line of though, say there's a 0 incline fairly bumpy road where on average there's 3 3cm bumps every meter and the vehicle is traveling 60km/

Continuing on this line of though, say there's a 0 incline fairly bumpy road where on average there's 3 3cm bumps every meter and the vehicle is traveling 60km/h (~17m/s). So the car has to provide energy to raise the car 9cm for every meter traveled. That's 1.5m/s vertically. So for an average car of 2000kg, we have to provide 2000x9.8x1.5 J per second, which is ~29KW. (That's gravitational potential energy mass x grav. x h) Wow, so maybe it's right. Or my math is wrong somewhere, or my hypothetical road is way to bumpy?