If my car was about to be repossessed and I hid it from the repo company, can the person who helped me hide it get in trouble?

Yes, that person can get in trouble, if he or she has any reason to know or suspect that you are hiding the car from the repo company:

1) Assuming the repo company (or rather, whomever they are working for, like a bank) has the right to take possession (e.g. you defaulted on the loans or financing), the car belongs to them--which means the person who is helping you could be guilty of some form of theft or receiving stolen goods.

2) That person could be sued by the repo company or their client (e.g. the lender or dealership) for any and all additional costs they have incurred due to that person's actions in helping to hide the car.