I did a compression test for my rx8, ever since it feels as if its gotten much worse, it misfires in first gear. Also when switching gears , i can acctually hear the gear being switched within the car. a thud noise comes up, what should i do? i also changed spark plugs coils and wires and still misfiring, all with the mazda recommended.

 

You should post this in the troubleshooting subforum.

 

You really haven't given us many details to work with.
You can try switching gas stations or moving to a lower grade of gas. It worked for me.
I was buying gas near where I work. Not a lot of cars using premium there. I believe the gas went bad. I switched to regular and I haven't had anymore problems. When I'm near my home I can fill with premium.