[kulangflow]

You can get the Apogee LOA. I use one in my Losi MRC and it works like a champ. It doesn't actually cut the throttle, but the screaming alarm makes you do it.

Edit: Scratch that. It looks like it's discontinued. You might be able to find one around if you look for it though.

Somebody around here probably has an old li-saver car version that they're no longer using.