That's pretty funny. I have the same VDO gauge cluster in my '85 380SE (ok, I have a 160 mph speedometer and a higher redline on a 7000 rpm tachometer and an Economy gauge) and I have never EVER had any kind of gauge problems in my car, except for when the fuse for the cluster blew (and fuses blow whenever they wear out). I also had VDO gauges in the previous '83 Saab 900S. Speedometer would be slightly jumpy around 15 mph in temps of below 20 degrees, but that was it. Fuel, temp, and tach gauges were always golden.

Maybe you need a gauge cluster with a higher speedo and redline. like in a gas 126.

-Sam