Volvo V70 2001 station wagon. Car accelerating and traveling in the 40 to 50 mph range vibrating as if problem maintaining pressure to hold the speed. Took to 2 different dealers - 1 replaced cars main computer (was under warranty)- problem was not corrected, then problem was diagnosed as a secondary computer, replaced at a cost of almost $1500. Problem appears to be reduced but still happens. Vibration in the 40 to 50 mph range --like the car is lugging in too low of a gear or not getting enough gas-- have been afraid to take car on highway trips because it was after/during these trips problem was most pronounced.

- Charlotte, NC, USA