The trunk of your car is considered to be a locked container. You just have to keep the ammo somewhere besides the trunk if you do it that way.
Okay, I feel stupid for having to ask, but I want to make sure. I'm checking out ammo on Winchester's website. My Glock uses 9x19mm. Is that 9mm Luger? It has to be, but why do they call it 9mm Luger?