w203 Speed signal location

I'm in the process to install a Clarion NVS613 Navigation, can please some one direct me where is the speed signal, I know there is a wire at the rear of my radio but on an other forum they are saying that the speed signal is send in the CANBUS.
Hope some one can direct me in the right direction if there is a propre speed signal in the car to connect my NAV.SYS, or do I need to buy a CANBUS converter.
Please someone Help


Thanks

[ILUVMILS]

I can check at work first thing Monday morning. I don't have any MB info at home. If I don't see an answer posted between now and then I'll post early Monday evening.

Thank a lot For your reply, your help will be verry much appreciated

[ILUVMILS]

I asked several colleagues this morning and they all raised their eyebrows! However I'm told that our local after-market installer has done a few NAV installations and knows what the deal is, so I'm sure it's no big deal. If you care to give them a call, the place is called Euro-Car in Red Bank, N.J. Good luck

Thank for your help M8
An other question for if you can help.
If I remove the power plug at the rear of the radion, will the radio go on PRODUCTION MODE????