Electronic key help

[American Saikyo]

So you get an item called Electronic Key. It seems like a key for for a car. So I used it in the parking garage and found the car it's for. It's at the very bottom. The car beeps and lights up when you use the key, but nothing else happens. You can't open it or anything. Am I missing something??

[Madness]

You can open the trunk for a shotgun and some bullets. I'd use the key again whilst in the general vicinity to get it to work.

[Riccioli d'Orco]

use the key while sticking very close to the trunk of the car
enjoy free shotgun bullets!