When driving my '06 c280, the SRS light will come on, the gauges go to zero(speedometer goes to zero) and then they return to normal and light goes off-this happens at least a couple of times daily and is quick when it does. If driving at night, lights go off also and then come back on.???????????

 

Sounds like you have a faulty instrument cluster. Hopefully you are still in warranty. They can do a short test and likely find CAN faults with the instrument cluster. This will sometimes trigger a check engine light too.

 

not under warranty-has 97000 miles. have any idea what a cluster will cost