I recently put one in my '90 535i. (Mine has the laser feature, making it a little more boxy than the radar-only unit.)

I tried all kinds of positions, but the need for the unit to to "see" forward and back really limits your choices. So I settled on a pretty conventional winshield mount, centered just below the rear view mirror using the supplied mount. For power, I routed the cord along the top of the windshield (wedged between it and the headliner)and down behind the driver's side "A" pillar trim panel, then under the dash. I picked up power straight from the ignition switch. (I didn't use the supplied power tap because the ignition hot wire was too thick. Instead I wedged the end of the power cord between the partially exposed hot terminal and the plastic surrounding it on the switch itself. Not elegant, but it works!)

The only visible wire runs from the top of the windshield down the rear view mirror stalk to the unit.

For me, this solution is just fine. You quickly get used to having the V1 in plain sight, and in this position it's also easy to remove it when parking in suspect areas.

The only problem I've had with the V1 is its well-documented tendency to cycle off occasionally as the high beams are selected. Doesn't happen all the time, but when it does it comes right back on line after a (startling, until you get used to it) self test.

The V! is absolutely the best. Head and shoulders over the 1993 vintage top-of-the-line Bell it replaced.

Joe