How do the cheap r/c remotes and garage door openers work?
I happen to know that garage door openers are often used (depending on how you define often) as wireless detonators for explosives, and for good reason. Like you said their cheap which is good but the unique thing about the garage door openers is that it is a encoded message so no stray radio waves will set it off
R/C cars I believe use a much simpler protocol because its not so critical. But I would guess that the more expensive the hardware the better the encryption