I just got a 2001 Mazda 626 just a couple of days ago, and the O/D off light started flashing on it.
It has a new engine, and a new transmission in it. So the miles on it aren't correct.
I was taking it to the dealership that I got it from, and the car broke down on me on the way there, it made a noise, cut off, and started smoking.
When I looked under it, it was leaking what I'm guessing is transmission fluid.
The cars interior is great.
But when the car shifts gears, it jerks.
Well you bought an 8 year old 144,000+ mile car, which the seller probably knew there was a fault with - you should have had it checked properly.
I don't think you can blame the car - that's a fair life for any car apart from an 80s Volvo or old Mercedes.
Sounds more like you got lousy service from a dealership, or maybe you didn't not have the car checked properly for existing problems prior to purchase. It's a bit unfair to judge the car as being lousy for a single failure, that sounds suspiciously like it was preexisting when you purchased the car.
I guess the warranty is up, huh?
If the car jerks, when you shift, do REV MATCHING. that's what the rev meter / rpm gauge on the dash is for.
Check the rpm for correct gear shifting and allways
don't take your foot complete off the gas pedal, if you do then the rpm falls rapidly and you have to press accl'tor
for correct rev matching so that wheel rpm and engine rpm match at gear.