What do you guys suggest about DIY?

here the installation guide this one will be a lot better than the come with compustar alarm this installtion guide for  authorized dealer use

http://www.compustar.org/support/manuals/install_manuals/CM3300_install_manual.pdf

I'm definitely not a pro, but you don't have to be a pro to know how to use a multimeter or have technical info on your car.  Anyone can learn to use a meter, and you can get a factory service manual for your car off ebay.  Most pro installation instructions will tell you how to find the majority of the wires you'll need.  Like this one.  Other than that, just take the time to learn to read the manual, get to know your car's wiring, and get comfortable taking panels off your car.

It's not that hard to do the install yourself.  The actual logic and theory behind an alarm install is quite simple.  I've done 3 so far, in increasing complexity.  The first was a clifford arrow 5 salvaged from a wreck.  It was supposed to have been "professionally" installed, but they took the same shortcuts most newbs did: t-taps, uncovered wires, accessible brain, etc.  I had no instructions and no knowledge of electronics.  Was mine a professional install?  Definitely not.  But its fully functional and, I must say, at least as good a job as the previous car.

For a clean install, you gotta RESEARCH, RESEARCH, RESEARCH.  Make sure you disconnect the battery, especially if you have airbags.  Know where you want to mount the brain, and where you want to run your wires, before you start attaching anything.  It means probably taking off the entire dash, so you can run your wires high and mount the brain out of reach and sight.  Use tubing to cover your wires, and tape them shut.  If possible, try to open up your car's existing wire harness, run your alarm wires in with it, and reseal the harness.  Don't leave wires dangling, uncovered, or zip-tied in a big cluster.  Those are all big signs that a thief can use to find the brain.

When mounting your siren, do it in an out of the way, hard to see, hard to reach spot.  Cover and disguise your wiring, and make everything as low key as possible.  Find a good grommet to pass wires through the firewall into the passengers compartment.

Lastly, you gotta be patient.  Don't rush.  Take the time to get to those hard to reach spots to mount the brain and run your wires.  The harder a time you have, the harder a time a thief will.

Anyways, I hope some of this helps.  Take it from one DIYer to another.  It's hard, but definitely not impossible.  You will learn a lot about your car, and if you do a good job, you can be assured of the quality and security you're getting.