C300Man

Those with VIM from mid city engineering or navatools how does it affect your speed read out? I figured with the unit it think the car is in park but its not. So the speed reading is not correct when its in speed, any drag when you press on the gas? Oh, would you recommend one? of course its not for me, its for the passenger and kids.

Diesel Benz

I'm not familiar with the navatools part but for sure none of these devices can affect the speedo speed reading if you mean that. Just the head unit speed signal should be affected.

Even the cruise control would stop working if the speed signal was killed completely.

Bokx_350

Just like DB said. The head unit thinks the car is parked (the VIM kills the GPS signal too, which the head unit also uses to determin if it is moving, so no navi while the VIM is engaged).

The instrument cluster has nothing to do with this, and it will read the correct speed as always. So if you were planning to drive with the VIM in order to keep your milage down, too bad