this is a typical problem with berettas, for some reason the bands in the transmission will not hold out after several miles are on the car, have the bands tightened or replaced, and you wont have any more problems
it is shifting gears
It might be that people toke it off or it might not have oil or the transmission doesnt work.
That's your clutch
i have a 95 es300 but it doesnt jerk when i change gears when i ride it jerks but i found out it was a motor mount front motor mount which will cost bout $112 to replace but if when you change gears it could be your transmission slipping that cant be goo but check your motor mounts first....
check the trans fluid.
Not knowing exactly what they did my best educated guess would be that the idle is too high.
Change the fuel filter.
May be its time to change your brake pads and rotors.
If a car jerks forward while in the break position it is not the Automatic Break System but rather the transmission.
no this will not ruin your car BUT it will start to scrape your gear because it is not being shifted properly
no you may need a transmission adjustment or maybe a new filter
An involuntary response is when the doctor taps your knee with a hammer and your leg jerks forward. A voluntary response is when you are angry at your doctor and kick him hard by swinging your leg forward.