Is it a felony or crime of any kind in the state of texas to hide a car that is up for repossession?

Yes, it is a crime, if the 'secured party' (the party who orders the repossession) has demanded the car be handed over to them, then it is a crime to conceal it. You do NOT have to have been informed of anything by the repossession agent themselves. The only notification is that the secured party wants the car back.

If you were to conceal the car in these circumstances, then under the Texas Penal Code, you would be 'Hindering Secured Creditors' (Section 32.33).

If the car is worth less than $1500, it is a misdemeanor of varying degrees.

If the car is worth $1500 or more, then it is a felony, of increasing severity for higher values.