Gotta concur on all this; I've just finished installing my Centech and Lo and Behold, everything works!
If all aftermarket products were this well made, the world would be a much better place. But I have two gripes:
1) The instructions leave something to be desired. I had to call them twice to get help which was quickly and expertly provided. Well written instructions, however, would have made even that little effort unnecessary.
2)The wiring is just different enough that they should provide a new basic schematic, which they don't. The explanation I got was that Painless would steal the design if they got hold of the schematics. I don't quite buy that; painless builds generic harnesses and I doubt they would be interested in building something as well made and vehicle specific as the Centech.
Two pointers:
Make careful note of how the old harness routs under the vehicle as you remove it, especially the left side rear by the tank filler hose and shock mount.
Some of the wiring on the harness is redundant, for older/newer vehicle designs. If you cut these and wrap them, make absolutely sure you know what you are cutting. Don't cut the brake light switch wires, and don't cut the blue right turn signal wires where they tap a common connector. Much frustration will result if you do.
Oh, one more thing: I recommend you pull the dash. It will be a major PITA (mmmm, pita) but will save you quite a bit of time in the end, not to mention a twisted spine.
Ed
Oh yeah, one more one more thing: buy lots of shrink tubing, zip ties, and cable clamps. And get a bulk pack of electrical tape. You won't use all the tape, but you will constantly misplace rolls and get angry hunting them. After you've opened about six, one seems to always turn up when you need it. Having about 5 colors of 14 gage wire can be handy too, if you have Duraspark.