i'm new here but i have looked and not seen this come up before. i have a 2006 cts-v 1 month old with 2000 miles and now have an intermittant speedo issue. it will jump around like from 30mph to 20 mph and back to 30 mph. twice on highway it goes from 70 to 0 and back to 70mph. when this happens both the digital and analog needle follow suit and always read the same. i called dealer and because it is not setting a service engine soon code and is intermittant they said they may or may not find the cause and suggest i drive till it quits working or is messed up all the time. i'm sure it is something simple like one wheel speed sensor sending missinformation at times. just not ready to give to a mechanic to drive the #$%$ out of it then say he can't find. has anyone else experienced this and was the cause found?