I get a lot of questions about installation, so I wanted to post some pointers and see if that was beneficial to folks.
If you've never installed before, the E9x isn't the easiest car to learn on. My recommendation for those who want to learn installation has been the same for years: Find a friend who wants tunes, and volunteer to help him or her. That's right, learn on someone else's car, just like most of the pro's do.
Things like how hard to pull, or pry, or push, are things that are learned by experience. They are tactile, not verbal, so if you want to be prepared before taking apart your E9x, you better practice on someone else's car.
This is the area where the early MECP training fell flat - you can't teach "mechanic's feel" (if you don't know what that is, I highly recommend Zen and the Art of Motorcycle Maintenance
by Robert Pirsig.
I hate crappy tools, and I grew up being taught that Snap-On, Mac, and Craftsman were what to use. Craftsman are good and readily available. Matco and Cornwell have come along since then and are also good. I don't recommend cheap tools.
I also strongly recommend against using battery-powered screwguns unless you use one every day. It is really easy to put a screwgun through a speaker, or strip a screw head, if you don't have excellent touch. Take a few more minutes and do it by hand. No reason to strip a bolt head or screw head.
You need 1/4" drive metric socket sets for more things than I can count. I think highly of Craftsman.
You need a 3/8" drive TORX socket/bit for the underseat bolts (T47?) so you need a ratchet for that. I think highly of Craftsman.
You need a set of TORX drivers for the door screws, the underseat woofer mount screws, etc. (Don't depend on short Torx bits, as they won't go deep enough into the door).
You need a number 1 Phillips screwdriver for underseat grilles (I've seen those crappy screws replaced with 2" drywall screws with #2 Phillips heads with no ill effects).
You need wire cutters (can be crappy, but they are frustrating) and crimpers (better get good ones). The cheapo flat-stamped crimpers are hard to use and your hand gets really tired, and you make bad crimps. If you are gonna do this more than once, get Kleins:
You need plastic door tools. These things are a godsend. We used to use metal tools with electrical tape wrapped around them to try to avoid scarring anything.
You really need a voltmeter. No excuse for not having one. Cheapo ones seem to work just fine:
If making an amp rack, a power saw, a drill, a tape measure, and a square are important.
Documentation and planning
- Electrical tape
- Heat shrink (various-sized kit) and a lighter
- Wire terminals, crimp-on
- Foam weatherstripping tape for speaker gasketing
- Black spray paint, flat/primer
- High-temp black silicone hot glue and a glue gun to "tack" tweeters into place (after snapping them in, I really don't want them failing out, and glue guns are cheap)
- Wire ties (a cheap side cutter helps keep them neat).
- Towels and old blankets (to set parts on top of other parts without scratching, especially around the HU dash area).
- Drywall screws can be invaluable. 1" to 1-1/4" for subwoofer mounting, 1-1/2" to 2" for reinstall of underseat grilles...
- Clear liquid hand soap (if pulling speaker wire into doors) and paper towels (for post-pull removal of said soap)
- Cheap Glad resealable food containers for screws and such so they don't get lost.
If you haven't taken it apart before, you may want to document the entire process, with a still camera, or a video camera on a tripod if you are really into that sort of thing. ON your own, a still camera is way easier.
Print out all the tech info you've found while searching. Keep it all together.
Map out your wiring at each end on a piece of paper, so you've got it in front of you when the time comes. If you can't do it on a piece of paper, you may not be able to do it in reality either (many pros can't do it on a piece of paper easily, but you're not a pro, either : ).
I'm a BIG believer in a "punch list" - all the tasks which need to be done, roughly in the order you think they need to be done, double-spaced, zand with checkmark boxes for bullets (I do mine in Word). The double spacing is for amendments as you realize what you missed. Print them out and tape them up to the side back window. Keeps me on the right path when my back is hurting and I start to make mistakes.
Feel free to overuse electrical tape as a temporary insulator to make SURE hot wires NEVER short against other wires, gear, or metal. Tear off a piece and use it to mask bare wire, then throw it away. That's what it's for.
A poor installation can make great gear sound crappy.
If you've never done mechanical work before, don't make assumptions that seem like common sense.
Don't assume that the pics of DIY work on the Internet are all good examples... too much DIY work on the Internet is by guys with more pride of accomplishment than actual skill. My goal is that it look like it might have been factory. Don't alter the intended use of the car or its functions.
Speakers need a baffle and need solid mounting. A baffle prevents air in front of the cone from rushing around the edges of the forward-moving cone, and filling the low-pressure area behind the cone. If you are mounting any cone driver and it doesn't have a baffle, it won't play as low a note as it could.
If you get frustrated or stuck, take a walk, or go get a drink (stay hydrated).
Stay off the cellphone. Pay attention.
Don't assume that this sort of work doesn't require intelligence because it involves wrench-spinning. I've seen mechanical engineers get their asses kicked by working on cars.
If all this freaks you out, either find a good pro, or go back to line 20: Find a friend's car...
If you are pulling the battery on an X-drive car, the warning light after you reconnect the battery will go out after circling the block a few times.
If removing or unplugging a seat, turn the ignition completely off, and do NOT turn on the ignition again until both seats are plugged in. You would trigger an SRS warning light that won't go out by itself...