Being that the car is right outside, as long as it made some noise before it gets cut off

I ordered my car with the OE (Alpine) subaru alarm system. If you have a basic alarm system, one addition you can make is an inexpensive pager. I added a $50 pager from JC Whitney, and, yes, it did wake me up the one time a bunch of local genii tried to remove my hood scoop. To install it, I just had to figure out which wire activated the alarm horn and I tapped into that.

If you don't have any alarm, then many of the alarms you could consider (such as Clifford) are now owned by DEI (www.directed.com). They have lots of options like pagers.