Interestingly, the speaker cable connections in the house are a nuisance with bad connections. Spring loaded connectors, even banana plugs, are just plain unreliable. Solder finally fixed them for good. (I'll solder on connectors, and then use a terminal strip.)
For the car, I also use rather expensive high grade stranded wire. I've been very happy with the results - the extra money pays off in time saved not having to repair them.