The 2.5 was one of the few subies that can also take a CR2032 cmos battery, a 3 cell lithium ion battery, or 8 D-cell batteries. Check with Autozone, as they might have one of these options in stock.
moisture in a connector. my old ladies impreza does this ever now and again.
distributor caps? i had this issue before and thats what was wrong.
i would hope that you are still not stuck at work
her dad got it started.