They already finished the install and it looks like everything works fine. Any tips for testing it?

 

Park your car in a high crime area for the weekend. If it is there on Monday the test was successful.

Realistically - read the users manual and installation instructions to fully familiarize yourself with the alarm. Then try to get into the car without using the remotes to disarm the alarm. If you find the alarm falsing regularly - you will need to have the installer re-adjust the vibration, motion and proximity sensors (if you had these installed).