i want to buy a keyless entry for my 2003 civic lx coupe. one of my friends told me that i need the stock radio to program it. is that true, or can i program it anyway?

 

If you don't have a stock keyless then you'll have to purchase one and that's pretty much pointless. Just get an aftermarket alarm system.
And your friend is wrong. You needed the stock radio for keyless entry for pre-2000 models (i think it was on 96-96 civics), so you're fine on that.

 

yeah an aftermarket alarm will be a lot cheaper also