it sounds as if the car has a limiter on it if the vauxhall dealers cant find out whats wrong with it then maybe you need to find out if its losing power through each gear the best way to find out if it has a limiter on it is to drive it through each gear until it reaches the red line on the rev counter if it loses power before the red line on the rev counter then you need to contact the head office of vauxhall as you will maybe need a new module for the revs i hope this has been some help any problems please contact me on 07766190088 thanks stewart
stewart
August 2007