My brother has a 2005 spyder, and when it is in gear, at idle..the engine shakes so bad that the dash vibrates...put it in neutral and it stops. Can anyone suggest the cause of this...someone told me a plug was not firing...if that was so, it would shake in neutral also (right ??) Thanks in advance for your help.

artie in miami

 

check your motor mounts, once the motor is in gear it will start to shake. if the motor mounts are good, check the tranny mounts too.