They probably don't have time for email at the moment.
They are out on the shop floor creating super tuning packages!
Aftermarket tuners is sort of an oddball cottage industry. Usually the owner is the chief mechanic/engineer, and so the business format is not as accessible as could be for the customer, as some other businesses like a new car dealership, or standard retail outlet.
We all know this isn't the best level of customer service, and it wouldn't work with a lot of our businesses. But thats the way it is with a lot of these types of "one-man-band" businesses. There is only so much time in a day to work, and sometimes they just run ragged. Growing past that stage, into a viable business entity that has good communications, and a solid business plan is the next step, and its a BIG step that takes time. Finding someone who can do what you do technically, and that you can trust to run the shop while you tend to the office, is one big hurdle, because trustworthy people are few and far between.
Reminds me of my own business path. I started out as a one man shop, (me), with ZERO income, and grew to 17 union field employees, and 5 office employees, payroll between $20k and $40k weekly, $5-6M annual gross and climbing.
Along the way, there were growing pains, (still are), and unfortunately sometimes things fell through the cracks. We are doing much better now, with a professional, scheduled, time managed, planned approach, and timely customer response.
You just have to understand the nature of these one-man-band businesses. They all have their faults, but good ones will prosper.