Paint shop jail... No parole!!!
I've been doing body/paint work for 30 yrs. What I'm reading here is that the guy doing the work has taken in more than he can do in a reasonable time frame. Nine projects should have four full time employees working on them. Pizz the guy off and your car will be put at the back of the line. Be polite but assertive that it's time to finish your car, your patience is wearing thin. If he gives you flack, take your car home and cut your losses.
Resto jobs are a HUGE labor intensive project. Unless your working on one 10 hrs a day 6 days a week, a year is not unreasonable. If you figure a job has 500 hrs of work at 40 hrs a week, that job will take three months to do.