Welcome to SCoA! The USA didn't get the 450 smart; most of the diesel 450 experience will be on the Canadian or European sites (Canada had 2005-6 cdi cars only). You'll also want to subscribe to Evilution - well worth the money.
A forum community dedicated to all Smart Car owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, economy, maintenance, and more!