deck install questions for 5th

i read some of the instructions installed in the lovely faq but i still have a few questions. the first one is do i really need one of those oh so very nifty volt meters. the second question is i saw a post that someones car wont start because he let some wires touch together or something like that . what are the chances of me messing this up so much that my car wont work. i guess thats it, i have alot of questions but i want to do some of the installs on my car myself.

What would you need a volt meter for? Pull the old one out -- and get your new harness connector, wire it to the harness that plugs into your cd player -- then plug it back into the stock vehicle harness and pop the cd player back in. NEVER EVER EVER EVER EVER hard wire it... you will thank me later!