Although the smart is a normal car in a small package, it seems as though they liked using some slightly less normal fixings. This is a growing list of things you may need when doing things to your car.
Selection of bulbs (see bulb list)
Bin liner or tarpaulin
Torx T10, T15, T20, T25, T30, T35, T40, T45, T50
Removing The Wheels
Torx screwdrivers T10, T15, T20, T25
Torx T40 for the tailgate support cable
Jack And Axle Stands
Changing brake discs and pads.
Lowering the engine.
Gaining access under the car
Any jack should be fine, personally I use an RAC trolley jack from Argos.
Always use axle stands after the car has been lifted.
Long Reach Torx Drivers
Torx Sockets (E Sockets)
removing brake disks.
rear suspension components.
5 Splined Torx Bit
Can be bought from smart, part number 450 589 03 09 00 or from here.
removing SE Drive.
unseizing bolts and nuts.
removing the front suspension.
Try your hardest to get PlusGas as it is the best.
Don't be tempted to use WD40, it isn't even half as good.
HT Lead Remover
Removing the HT leads from the sparkplugs.
Can be bought from smart, part number A 638 581 02 67. Thanks to Peter Sharp for the picture.
Oil Remover Pump
Sucking the oil from the engine during a service.
The best pump in the price range is the Pela 6000.
Accessing awkward nuts and bolts.
Fitting the upgraded earth lead.
Magnet On A Stick
Rescuing droped nuts, bolts and other fixings from the engine.
Retrieving things that roll under the car.
Removing the plastic pins from the centre of some smart fixings.