Good soldering skills, and a good soldering iron, are worth untold amounts of money (and joy)!!!
I picked up a Weller WESD51 soldering station (with digital temperature read out) on sale a few years ago. Best $130 I ever spent. It's good not only for car audio (as I learned last week) but also for repairing anything with wires.
Coincidentally, the WESD51 is on sale again on
Amazon right now:
Weller WESD51 Digital Soldering Station - Amazon.com
(regular price $200, on for $131 now)
The Weller iron is a high quality unit, the tip is sharp and gets hot quickly. More than worth the money. The crappy $25 soldering irons are so frustrating and unpleasant to use, and make your work look like crap (speaking from experience!). Generally if someone says soldering
sucks, it is because they tried a bad soldering iron that was hard to use and they did an ugly job.
Last week I fixed a couple of car starter remotes for my neighbour. The part the holds the coin batteries had worked loose, and a bit of solder made them work like new. Two years ago I rewired my truck and trailer with new connectors, and soldered joints ensured the repair will last for a long time. Last summer I did a lot of wiring work on my motorcycle (1986 Honda Shadow 750cc) and soldered and heat-shrinked all the joints.
Don't forget to get some good heat-shrink to cover all your solder joints! Transparent heat shrink is the best because it lets you visually inspect the connections. Using electrical tape is such a waste of time and risks breaking the joints from repeated flexing as you warp the tape on.