ALWAYS trailer your car in neutral.  If your straps come loose and the car rolls backward while in gear, being in neutral prevents the possibility of de-tensioning of the cam belt, so much so that the crank can slip a cog or two, maybe three.  When the crank becomes out of time with your cams, your hosed.  The car can't start, no worky!  The worse part is that you have a high probability of bending valves if you slip a cog when cranking the motor, assuming you're using stock Subaru pistons.  If you're using Outfront's "non-interference" pistons you won't bend valves in this scenario in most cases.  But it still won't start until you re-time your cam and crank properly.

If you don't know how to re-time your crank and cam yourself, this is a good thing to learn.  This knowledge can save your weekend.  SOHC setups are very easy, DOHC setups are a little more intricate, but not tough to learn.  It's also nice if you have an Outfront exhaust setup so all this can be done without removing your exhaust, turbo, and intercooler.