My 1999 e 430 has only 29,000 miles and it runs fine - I took it to the dealer for climate control malfunction under extended warranty, they changed the thermostat and everything seems to be okay; however, they gave me a list of maintenance items (worth $1,700) that should be taken care of - one of the items is "change the plugs" and tune the engine.

Is it necessary to change these platinum plugs after 29,000 miles; although they have been in there for about 5 years? Also, is it difficult to change the plugs?

The flexible (automatic) maintenance system of the car has not indicated any engine work maintenance - nevertheless, the dealer recommends it.

Any comments?

Thanks!