This is a great idea for all you guys out there that still don't have an alarm.

You know how every deck has that bolt and nut on the back that is hardly ever used?
Get some steel braided cable and bolt one end to the back of the deck.
feed the other end down inside the dash all the way to the floor as you slide the deck into its spot in your dash.
once the deck is locked into the sleeve pull the steel braided cable tight and bolt it right to the floor or something strong.
Now there is no way anyone could pull that deck out.
And your the only one who knows where that bolt is that needs to be removed before the deck can be removed.

I like that idea. :)

well the problem with the razor blades, is

1) thats illegal
2) blood stains (which a lot of thieves may not have untainted blood.)
3) what happens when they slice themselves?... they might get vengfull, and even though your system is still there, it and your car may be bludgeoned a few times with a crowbar :P

Back in the day a lot of guys liked to use a wack load of 120db Piezo sirens installed under the dash and wired to a back up battery.. man 8 of those and there's no way you can stay in the car lol

Yeah I have my backup battery siren under the hood and my regular one under the dash.

the one customers H2 had transport truck airhorns that would go off with the siren stupid loud

I also want to endow my car some alarms so it will stay protected from thieves. But the problems is I have a low credit scores and I don't know how to manage transforming my car into a much safer one.

was gonna suggest that, train horn in mine, does the trick, will wake anything/anyone up

how about wiring your car to have positive charge from the battery so you have 14 v going through the entire frame of the car , but when they go to touch anything they get shocked. like switching positive and negative on your battery. i always make my boxes so they are impossible to be stolen and wedged into the trunk. also having the amp out of sight when you open the trunk is key ( spare tire area ) or leave a baby monitor in the car and another one by your bed while your sleeping....
what i liked about my jetta is i could lock the back seats up and the trunk button to not open with my keys....

another good idea is

u ever try getting a shock from 14v dc?

u can grab both posts on a battery and lift it and u dont feel anything(not a good idea tho)