Smart City/Cabrio/Fortwo 2003-06 suffer intermittent battery discharging, due to a current draw above the recommended 50mA. This can normally traced back to the instrument panel. About 50% of these instrument panels can be repaired at low cost. Its worth having these panels bench tested due to the high replacement cost involved.
0.8D CDi 1999-06 799cc three cylinder OHC diesel engine fitted with common rail injection is a real gem. Downside is they are only fitted to LHD vehicles. Have seen one conversion of a petrol 42 bodyshell with this 80mpg+ engine fitted.
Smart City Coupe suffer fuel cap release solenoid failure. Only way to refuel the car, till you replace solenoid and lubricate the mechanism. Is to remove the rear lamp plus remove the sound insulation fitted behind & pull locking mechanism towards rear of the car to release the fuel cap.
Smart Roadster/Coupe suffer lack of power. Reason being, control rod connected to the turbo wastegate regulating valve, is not up to the job & works loose. Nobody in the trade knows the specification for re-adjustment, so its a matter of trial and error!
Smartcar 42 Service Light reset procedure
1.
Turn On ignition2. Adjust instrument display to show ‘Maintenance’
3. Turn Off the ignition within 10 seconds (‘Maintenance’ should remain in display)
4. Press and hold the service button which is located on the top left of the instrument ‘Pod’ while switching the ignition on.
5. Hold the service button for a further 10 seconds to reset the Oil interval
6. Check instrument display for remaining distance until service
Nobody in their right mind, attempts to change the lower spark plugs on a
Brabus Smart coupe unless they have too.....! Trade book time is 0.6hrs.
Its more like a two hour plus job.
Personally
I like the concept of the
Smartcar 
But be warned they are not the easiest thing to get repaired. Many
independent garages will not touch them at all. Other garages will attempt
repairs but are not equipped to complete the job properly. Many of our
customers travel from far and wide for us to repair & service their vehicles.
The nearest garage to us, who also offer specialist repairs to Smartcars is at
Cambridge, 45miles away.
Page updated 28-05-18