Making a car difficult to steal

In addition to proper wiring and alarm install there are other things to look into as well. You will never completely stop a thief that wants your ride, so slow them down and make it a pain in the butt to steal it. They will then move on to an easier target. For starters Look into a battery relocation kit for the trunk and a hidden disconnect. A separate backup battery hidden for the alarm system is a good option. There are many things to add such as column locks, pedal locks, steering wheel locks, you can use a large master pad lock on a B&M shifter so it won't leave park for example... Also wheel locks work well and there are police issue boots to make it un-movable. Theres Locking car-covers and locking hood pins. There are many other options available as well as custom DIY stuff such as baby monitors or switch wired thru old am radio etc...external surveillance systems work as well. We also have enough neighbors that work different shifts that Someone is always outside and watching. Especially nosey retired neighbors with nothing better to do, lol! Yes it's not full proof, The object is to slow them down enough they will move on to someone else's car as yours is too much trouble. They want to be in and gone in under 1 minute.......
When traveling keep doors locked and a large wrench or weapon of choice near by. No one will bother you. Had a guy run up to my drivers door years ago and tried to open it. I pointed my legal concealed carry weapon at him and he went away.

In addition to multiple security measures, I sleep right on the other side of the window with a rifle waiting as I don't sleep that well at night anyway. I pity any fool that tries. Lol!