Comedy ScienceFiction; nerds are prepared to save world, wearing rubber bands that protect from beam

Hi guys,
I am looking since long for this movie, I hope, You can help.

I guess it’s from about 1990’s, not sure.
It’s a funny movie, about aliens attacking the world, being fought back by some nerds.

A few nice guys, Nerds, know everything about aliens, apocalypse etc. At least one of them has survival bags/rucksacks already packed and srored in a room for the different possible catastrophies, like: alien attack, zombie apocalypse, a.s.o.
They often discuss these topics.

When aliens attack, they go for the bags and find the one for “alien attack”. Now they are protected from the deadly laser beams, because they wear rubber bands on their arms, that protect them.
A real mean bully laughed at them because of the rubber bands but I think he dies, because he doesn’t have one.

Their car is still running, because they wrapped aluiminium foil round the engine’s electrical parts, all the other cars don’t work.

These nerds are the ones, that may save the world, because they are prepared…….
I think they go for a radio station or something similar.

That’s all I remember.

I do hope, that someone may be able to help me,
thanks a lot in advance!!!

Greetings, Arti