What are estimated annual maintenance costs for the 300E vs. 420E? I assume insurance and gas would be similiar. Another reason for considering the 300E over the E420 is that appearance wise it is in almost perfect condition. This car has over 100K miles but there aren't even any creases on the leather seats or and door dings or paint chips. The only problems I've found with it so far are that the A/C does not blow very cold and the engine stalls when first started up and is very sluggish until it gets warmed up.