This has been happening .. at least in calendar year 2023, maybe as far back as last year? It happened a couple of times the other day in heavy traffic. My guess is when the car shifts from 1st to 2nd gear. I have an LX with the 5-speed auto.

The car literally / violently "bucks" / lurches forward. The first time it happened, I seriously thought I was rear-ended.

Could that be a .. cv joint about to fail? Possible in-need-to-be-flushed transmission fluid?

It is a 2008 with ~ 115K miles on it. Always parked outdoors. I'm starting to have stuff go on it.. Just the other day the starter went, and then the alternator froze up, too.

 

I'd check the transmission fluid level just to see if you have enough fluid.

A bunch of items can cause the transmission to shift harshly.

If you have a parts store or a scanner, just check for codes to possibly give you a direction for testing.

Pay attention to when you have the bucking. Does is happen when your gears are switching? Only when the engine is warm/cold/all the time, etc.