Replacing rear wiper motor on a 2006 smart fortwo

Do you know how these wipers Work / what controls them ? Do you know what a smart junction box is ?
Rear Window Wiper Operation
The rear wiper motor is controlled by the SJB. The SJB supplies power to the rear wiper motor from the integrated rear wiper relay. The SJB will activate the relay when all of the following conditions are met:

• Ignition switch is in the ON position
• Liftgate glass and liftgate are closed
• Multifunction switch is in the ON or INTERMITTENT position

The SJB also supplies voltage to the rear wiper motor from SJB fuse 21 (10A) when the ignition switch is in the ON position. This power feed is used to continue the wipe cycle when the multifunction switch is turned to the OFF position. The SJB receives inputs from the multifunction switch that applies ground to the low speed wipe input or applies ground to the intermittent wipe input. When either of these circuits are grounded, the SJB activates the integrated rear wiper relay and power is supplied to the rear wiper motor to move the rear wiper motor from the PARK position. An internal switch in the rear wiper motor then moves to the RUN position which connects the accessory relay power to the rear wiper motor. When the rear wiper motor returns to the PARK position, the internal switch in the rear wiper motor moves back to the PARK position. If the multifunction switch is in the ON position, the rear wiper relay is still activated, power is supplied to the rear wiper motor, and the wipe cycle starts again. If the multifunction switch is in the INTERMITTENT position, the rear wiper relay does not activate until the predetermined dwell time has elapsed, at which time the SJB activates the rear wiper relay and the wipe cycle starts again.

Do you know what DTC'S - diagnostic trouble codes are ?
Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1244 Wiper Rear Motor Run Relay Coil Circuit Failure SJB If the rear wiper is inoperative, Go To Pinpoint Test B . If the rear wiper is always ON, Go To Pinpoint Test D . B1245 Wiper Rear Motor Run Relay Coil Circuit Short to Battery SJB Go To Pinpoint Test B . B1614 Wiper Rear Mode Select Switch Circuit Failure SJB Go To Pinpoint Test D .
Did you have it checked for DTC'S ?

You can try this site MERCEDES BENZ CAR RADIO CODES

http://www.fixya.com/cars/t4194955-location_diesel_filter_2006_smart_car

A slow shutting of the clutch ist somewhat normal if you jumpstart the Smart 450. But it could be improved by teach in the clutch or replacing a weared down clutch or a stucking actuator. Another possible improvement is replacement of the front motor bearing. In this case build in the stronger bearing of the diesel engine.

Doubt that very much , as Smart has a very strong security on it

2 small grills below wipers. Each has a slot the size if your key use key to give it a 1/4 turn then you can lift out the grill. One side has an airbox under the grill this will come out with a tug. Then you can reach backside of headlights

when you turn on the wipers , look at the main screw that is holding the wipers if it is moving while wipers are still?

that is a little tricky , you need to dismantle the upper spoiler and see where is the pipe to be connected

dont know much about them cars but if the fuse is good its most likely the wiper motor

As there are not many of your car on the road yet most autopart stores do not have these on the shelf for you. I expect you'll need to locate your closest dealer and obtain from them.
I hope this may have helped,
Tom