if car idle at traffic light then your car will be more shaky (compare to when new)

and vibration sometime will reach your steering and car cabin
this is also why 3cyl ppl complain will shake and kill the mounting
because odd number cylinder vibration doesnt reduce/cancelling vibration on each combustion cycle

still will degrade ..just wont be as fast as odd number

just did some weeks back , now not vibrating so much

rx8 , price cant remember excatly , i think about rm 900+