actually very easy to do on subarus.
the major problem that most people have on stardard transmission cars is that if you leave it in gear and remote start it, it WILL drive off, and with some force too.
luckily subarus have a 'neutral position sensor' on the tranny. most cars only have 1 plug to the tranny (reverse) so that the lights will pop on when you put it in R, subarus also have one that senses neutral. i'm not sure why. so all you need to do is be smart enough to wire it so that it will only get power to remote start if it is getting signal from the neutral switch (which isn't really that hard to do).
i'm actually going to be installing my alarm/remote start the same way pretty soon here. i would have done it at the garage day if i hadnt been made of 15% tequila the night before.
