I have a question !!
How many spark plug?
The car at the parking RBM is not a fixed rise time and fall time so that he sometimes turns off the car and there is a kind of shiver
What do you expect the reason you can be of plug wire and spark plug

 

^4 plugs.... no i dont know why u car is doing that... maybe the alternator is failing or battery is low....thats why most cars shiver.... SHIVERs can also be a BAD MOTOR MOUNT...

 

you own an rx8 and dont know how many spark plugs it has?.... once you fix your problem sell your car to someone that will take care of it

 

+1.