There are two things that you will never find in my rally car. ‘Vampire Taps’ & ‘Butt Splices’. The first is an absolute NO. Vampire taps only work under ideal conditions and wire thickness. Too big and they make a poor connection, too small and they chop the wire in half. Both of these failures are acceptable for stereo systems, but not when you’re hooking up things like intercoms and rally computers. If you have to make a tap, trim away the insulation with a proper wire stripper, wrap the new wire in, and solder.
The second item has been part of an argument for ages, so I’ll give you my take. I hate butt splices. Even if you have a $50 proper crimper and you use the non-insulated ones and cover with heat-shrink, I just prefer a soldered connection over a crimped one. Wires are more likely to get pulled out or snagged in a rally car and that’s when butt splices fail. Here are two good articles on getting it right: Soldered Lap Splicing of Wires – Master a perfect inline wire splice everytime
This post was inspired from the vampire tap clean-up that I had to do on one of the wiring bundles in the 2GN. A previous owner had an aftermarket alarm installed and several of the taps had either severed or broken most of the copper wire it was clamped to. 🙁
I’ve had my eye on 12v resettable fuses for a while now and it’s something that I think will really come in handy on a modern rally car. The E-T-A 1620 series are automotive grade circuit breakers that fit in a “mini fuse” space. Around $5 each they beat a zip-lock baggy of replacements in the ash tray. Along with these I ordered a number of switches for the cockpit panel and some some separate 12v circuit breakers for things like lights, rally computer, and transceiver. I also ordered some spare Molex type connectors to better interconnect the harness in the rear of the car. I will be able to change out the melted and cracked connector that goes to the lights and blinker switch. 😮
Zip-ties, duct tape, and bailing wire are the most common MacGyver items in a rally car. When a rally is in town, we usually have more spare zip-ties then the local Super Walmart. Zip-ties are a rally essential, but you need to pickup an essential tool for installing them: A pair of 
I took the rear doors down to what I call a ‘safe minimum’. I’ll leave the glass in for now, but there is enough metal to support the window and keep thieves out. The inner metal only accounted for a pound, but it gave me better access with the grinder / sawzall. The door beam weighed in at 4 pounds. The window roller mechanism was a pound. I’m estimating 7-8 pounds off of one door with the plastic trim, all the bolts, and the metal cut out. 28-32 pounds saved on the car from all 4 doors.
Next I had some fun with science. My local grocery store had dry ice available, so I picked up about 8 pounds of it. The clerk handled it much like a radioactive isotope and I was asked by a little old man in line “What do you need all that for?!” I responded quickly and with authority – “It’s a science experiment.” Then I grabbed the top of the bag with bare hands and made it out the door. “Be careful!” they shouted after me. :p Guys, it’s minus 80 cold, not minus 300 cold… Wear gloves, but it won’t instantly kill you if you touch it with bare hands. “You could get frostbite! OhNOES teh frostbite…” Broken up into chunks, the cold hardens and contracts the 1/4″ thick tar sound deadening. After a couple of sharp blows with a hammer and some scraper work, about 15 pounds of sound material hit the trash.