Front parking alert system

[68EFIvert]

Many of our cars are pretty low to the ground and/or are running splitters which can cause some problems with parking curbs. I am thinking about adding in a parking alert system like the new cars have to my 1968 Volvo 1800 I am building. Have any of you added such a system to avoid the chance of doing damage to the front of your car? It seems like it is cheap insurance to body damage. Here is what I am looking at.

http://www.crimestopper.com/products...assist/ca-5017

I am only looking for an audible alert system so I don't have to look at some ugly LED display and the speaker can easily be hidden.