A tip to prevent this in the future, as my entire car is loaded with stripped screws (I bought it used that way, unfortuately). For any screw on that car other than the motor mount screws that go into the bottom of the chassis:

1.) Buy straight line allen drivers (not L bend ones) i.e. the ones with handles NOT the ones without.

2.) Only tighten them in as far as you can by hand (this is why NOT to use the L bend wrenches, as they give you too much leverage for such small bolts). Do not add prybars, extensions, or whatever. This 1/8th scale car here, these aren't two inch lugs to hold a tractor toghether.

3.) If the screw comes out, use BLUE (not RED) loctite. Or, if you are the paranoid type, just loctite everything in advance. Blue is for light to medium duty applications like this. Red is for bonding high temp. high stress stuff. It is designed to be damn near permanent, which is bad on a car that most people will take apart at least 10 times.

You shouldn't strip screws unless you are trying to tighten them too tight, or if you are lazy and you stuffed the wrench head in the bolt while it was full of dirt therby not getting the full ammount of sidewall to grip the wrench, causing it to slip, and strip. Either way, its generally not the screws or the tools fault. Its usually operator error.