2002 Conv

[KyleMiller]

I recently bought a 2002 330 Cic without the factory alarm. I want to install one that includes motion dectection for when the top is down. Should I go with the fatory unit and can I install it myself, or should I use an aftermarket. If so, which one.

[MarvelPhx]

Get the OEM alarm, it uses a microwave sensor instead of the ultrasonics the hardtops do...

I don't believe that the US version of the OEM alarm has a motion sensor. Is this correct?

Is there a way to ADD a motion sensor to the OEM alarm if it doesn't have the motion sensor?

and.......What is the difference to the user between ultrasonic and microwave?