Can I ask a few questions? You may not want to answer them, but it may help us give a more comprehensive bit of advice...
This is not by any means a dig, I promise, I'm just trying to look at it from the "other side of the coin" purely to help you decide what to do for the best.
1) You say Jue's given up his job in order to work on cars from home. Is he registered (with HMRC) as a sole trader or other form of company?
2) Taking number 1 into account, is the work being done from home?
I suspect based on what you've said the answer to this is yes - have you registered with the relevent organisations that you are conducting business activities at your premises?
3) Are you working on the cars on a driveway, or on the road?
Just be careful, if you're not fully legit in many areas, people will look for these weaknesses in order to strengthen their complaints...
