This car has been a tank... no problems at all since buying it new, until I took it in for maintenance last month and had my first non-maintenance repair ever... dum da da dummmmmm... two rear license plate lights. Pushing 200K now, and there's this weird vibration that I've been feeling occasionally. It happens at low- to mid-throttle acceleration at low speed and most observably when the hybrid battery gauge is low. It feels like engaging first gear from a standing start in a vehicle with a manual transmission that has a warped clutch plate. Sometimes I will hear a rattling sound, appearing to come from under the hood, that matches the vibrations. I can also feel vibration when I'm at pretty much any speed and low throttle (such as if I'm on cruise control), though it's most noticeable at highway speed. (At these times it feels like something in the power split device can't decide if it wants to be engaged or disengaged.) I notice this mostly when the engine is already warmed up, and it is noticeable when the hybrid battery shows "normal full" (6 bars) though not as much as when it's low. The engine idles fine, runs smoothly under all conditions with no feeling of "missing", there is no vibration at speed if I'm coasting, and I can get the vibration to stop by stepping the accelerator down harder and getting more vigorous acceleration. No "check engine" or dashboard lights of any kind. I just got a new set of tires and rear brakes, and had the front brakes adjusted, so they can be ruled out as suspects. Toyota dealership multi-point inspection revealed nothing, though I didn't mention this issue for fear of severe financial agony. It legitimately feels like there's a warped clutch somewhere in the power split device. Anyone else had this issue? If yes, what had to be done to fix the problem?