alarm antenna under headliner?

I just had an Compustar alarm/remote start installed on my truck over the weekend. After the install was over there was a huge ugly antenna stuck to the windshield above my review mirror. I asked them about that and the installer said its to get the best range. I stared to think about that later on. The only time I will start my truck is from inside my house which is like 40' away. So I would say I just need like 100' of rang max. Can I just pop this antenna off the windshield and slide it up and under the headliner?

The official answer is they stuck it in the best place. If you go under the headliner your metal roof might block too much signal. It's up to you.