A month ago starting on the motorway the car started to shudder with the same sendsantion of going over some rumble strips. Took the car back to SAAB( under warranty, purchase only in March) and was told that the "regen" was not responding on manual. Told to carry on as normal but arranged for a check up. Found that 2 of the "glow plugs"(?) were defective so they replace the complete set of 4. No problems for 2 weeks driving only locally. Last Saturday drove up to London (150 miles) at 70 mph and eventually caught in the jam on the M25. Whilst costing at 40 mph the car started to shudder so violently that I was tempted to stop but carried on gingerly. No problem since after having come back again 150 miles at 70 mph. Is the shuddering normal or is something else to look at. I have owned SAABs for the past 20 years and this has never happend before. I am concerned that something may happen. I noticed obviously a loss of power, icreased the speed but returnind down it started again. No smell of burning at all.

Any advice or suggestion.

dleoni