This may not exactly be the correct place to get this answered, but i'd rather try and get info from professional audio engineers than from random petrol-heads - please tell me if i am off-topic.
I am thinking about building a custom enclosure to put a pair of sub-woofer speakers & an amp in the boot of my car; I have seen people who just buy thick plywood & mount the speakers without much care about anything else, i have also seen professional car audio techs who put a lot of thought into their enclosures to the extent of - what i believe i heard anyway - creating ports from the internal 'chambers' that have a width relative to the wavelength of the sounds it will be producing, is this sort of stuff necessary? I don't want to go over-kill but i do what to take the correct amount of care to not ruin the sound.
The speakers will mainly be used for showing off at car events looking flashy & unique, so I guess i don't need to worry too much about sound quality vs how they look, but in honesty i tend to be a bit of a perfectionist and want to understand exactly how something works before i just go and do it willy-nilly.
Are there any pitfalls to building an enclosure to house a subwoofer that should be carefully planned around? Are there any commonly made mistakes that can be avoided?