I ran a shop for six years, and was a dealer for PG, PPI, Memphis, and Eclipse. My advice is this:
Only buy mass market product (headunits, alarms, video equipment) from a distributor. The prices on these products are burned by their wide availability to the point where being a Pioneer or K9 dealer has no significant advantage over just getting the stuff from a distributor. Buying Kicker or MMATS from a distributor is a bad idea not only because you'll pay significantly more, but because you'll miss out on various dealer programs (earning points, % off a purchase over a certain amount, special sales, etc.)
Make sure you buy reliable product that won't take a dump on you. When PPI switched to offshore production the first couple batches of their amps had something like a 2 in 5 mortality rate. Customer comes back pissed off, you waste your installer's time switching out the amp, customer comes back again even more pissed off, you try to get the customer to upgrade to another amp, etc. It ends with you dropping the line, losing money, and probably losing a few customers because people think you sold them junk.
Do not do the "window into the install bay" idea you were talking about. Yes, real enthusiasts would appreciate it, but the occasional gangbanger/old man/soprano wannabe type loser will turn it into a nightmare. I know because I did this before and it was a big mistake.
Buy cheap and reliable alarms. Alarms are the bread and butter of many shops. I'd suggest selling K-9 as your cheapest (it's been scientifically proven that the K-9 Mundial system is capable of withstanding an EMP blast). Then get a cheap remote start and pager system like Autopage and something you would use yourself as your top brand.
As far as lines are concerned, I think you have an excellent choice with Memphis. Another nice line to carry would be Eclipse because you can get their electronics which are one of the few electronic brands NOT commonly available through distributors. I would suggest carrying Memphis, Eclipse, JL, Morel, and Zapco. Then buy a few Lightning Audio amps and Pioneer coaxial speakers from a distributor for the broke highschool kids. Diamond, ID, ARC, and CDT are nice too but would be redundant in the lineup above. In any case, Memphis and JL would be a great start. Depending on how upscale you want the shop to be TRU, Genesis, Brax, Butler, and Dynaudio or worth looking into as well.
Don't have a bathroom for customers. You don't want these mother****ers hanging out in your shop, you want them to buy something, give you their keys, and get the **** out. They'll come back and give you more business if you give them a good price and do decent installation work, not if you offer them a massage and aromatherapy. Have three or four CHAIRS (not a sofa) in the waiting area and keep the bathroom next to a storage or woodcutting room. ALWAYS suggest they get someone to pick them up or call a taxi unless you're doing something quick like a head unit or basic alarm.
Provide services in addition to car audio. Tinting, rims, accessories, etc. Maybe rent a shop in a building that already houses someone that does bodywork and paint if you can find a situation like this. It'll bring more business.
Finally, don't open a shop unless you're absolutely sure you want this. Some people are doing okay, but most are struggling. If you want to do something in this vein open a home theater/home automation business. That's where the real money is right now.
Just my two cents. Good luck!
