Im all for installing yourself. I had a viper alarm installed by car toys, with an engine kill. After about a year my ignition started acting a bit wierd (wouldnt catch right away...or not at all).
So I looked into the wiring from the ignition back....UGHHHH....when they wierd in the alarm they didnt even bother with butt connectors, they twistied up the wire splice to the ignition and wraped it in electrical tape.....all the connections were like that.
After a year the main ground to the iginition switch had loosened up. I ripped it all out and hard wired everything with solder. The install looked like it was done by monkeys fresh out of the zoo.
I asked around about car toys install jobs, come to find out they usually have one "good tech" and he/she is always out, leaving snot nosed brats to just tape it all together.