I would look in your area and see how many other compaines in the area offer the same thing, including prices if possible. Personally I would need to get an amazing deal (like 75% off) from a new company to over look a company that has been astbilshed for many years.
Honestly I am a graphic artist and I do screen printing. I do not have the semi professional machines or professional machines because they are pricey. I borrow from another friend, we trade off the random paying jobs we get to make items. Both of us has a degree (FOUR year of college) in the arts and after seven years we are still struggling to get off the ground (have not made a profit yet after seven years, but getting close). We both have other jobs; she is a photographer and stain glass artist (this also has not made a profit for her yet) while I am a part time event supervisor at a local college. So we have other sorces of income.
Now you did not mention if you or husband have an art background degree. If one of you already are in that niche then you have the starting knowlage to build a fondation on, just a few classes in the next few months is not going to give you the same level of expertise that other screenprinting compaines have. There are MANY online compaines I would go with over a new just starting company because I can design for free with them and the quality of their items/design are by far better then a few months of design class.
In the end if this is something you are really passionate about GO FOR IT. Just so you know that it can take 5 years (or more) to turn a profit so plan for that. The machines for professional grade quaility are pricey and takes a few months to really get use to using and making good quality items (trust me a screwed so much up at first because it takes awhile to learn how to use).
EDITED: I am sorry if I discouraged you, that was not my intention. I just wanted you to be ready for what is ahead, I would hate for you to put tons of money into and then stop after a year. It is a lot of fun if you enjoy designing, creating and making the items. Now talking about car graphics that is a whole different area then shirts, not sure if you need a specail/different machine for that then shirts/hats and so on. That is a much larger scale but there is only a handful or less in my area that does that (maybe should look into that area) but those are very specific materials that will need to be used so do look into it. There is no harm looking into it, price things out, figure out what you need, start up cost, cost of materials & supplies and then specail class prices.
Seems you have people you know that would be intrested, you are thinking about it so it might be something you would enjoy so give your idea some more thought and do not be afriad to dream (just look at the whole picture and see if that dream will fit for you, your family and area of buisness).
