For an alarm, I would put it on the A pillar or up in the dash near the windshield. I chose the location for the LED's for the radar where I would see them without having to look away at them. They are in my line of site while driving. It doesn't matter if my hand is at the top of the steering wheel, or on the side. Either way, I will be able to see when they light up.
The radar is a K40. Similar to what I had in the truck, but I let it go with the truck when I sold it.