Can the repo man take your car with cars behind it?

This can only be interrpreted that you are asking whether it is legal to hinder the recovery of the lender's property. The answer is no. In some states, if you actively or even pssively attempt to hinder the legal repossession of a vehicle for which you have not paid the loan, you could be arrested and charged criminally.

Now, literally, provided the agent is able to secure the vehicle, does not violate any federal, state, or local laws, and maintains the peace, yes.