I work at a car wash. We are only clocked in and paid while on a vehicle. Is this legal?

The law obligates the employer to pay you for all time you are in its service. (There are some exceptions for on-call employees which don't appear to be applicable to your question.) So if I understand your question, the employer is not paying you for the time you are on the job and at the employer's location but not actually working on a vehicle.  If my understanding is correct, your employer is probably breaking the law. 2 free but not very speedy remedies. First, call the Texas Workforce Commission and ask about filing a "Payday Act" complaint.  This law allows the TWC to go after an employer who does not pay its employees all of the pay they are due.  But don't delay, they can't collect any amounts over 6 months old. Second, contact the U.S. Department of Labor, Wage and Hour Division.  There is one in every major metropolitan area in Texas.  Dallas and Fort Worth share one in Arlington.  They are responsibile for ensuring employees are paid minimum wage and overtime. Finally, you could contact a labor and employment lawyer in your area, but this may not be an economical solution unless a group of you are willing to go in together. Good luck.