M35 lacks a front parking assist sensor: any good options?

[kj2005]

The M35 has a decent rear parking assist with the camera, however I would like to consider options for a front parking assist. Has anyone found one they like or know of one that would work well?

I am not interested in bumper mounted sensors where you have to drill holes, nor am I in need of a LCD camera mounted on the front license plate. Basically, I was looking for an audible sensor that could be built into or attached to the front license plate frame. The rear parking assist sensor get their power from the backup lights but that clearly does not work for the front. Maybe power would come from batteries or the car battery itself however how to enable or disable the sensor to not drain power would be problem.

I've seen plenty of rear mounted parking assist setups and wonder if some could be used in the front of the car instead. To give you an idea of what I had in mind look at this link to see what I was thinking as an example. http://www.smarthome.com/91714.html

Any ideas or solutions would be appreciated.