My mother in law is of sound mind and body and wants her hired help to use her car to drive her to appointments and so on. The son with DPOA wants to sell her car. The money is not needed right now.

As long as she is in her right mind, she can counter her son's wishes. Technically, he shouldn't act unless she can't.

Does she know this is in his mind, to sell her car?

She can remove his DPOA. I would, if I were her. It doesn't sound like he has her best interests at heart.

Thanks! That is what I thought. He has not told her yet, just me. The reason a DPOA is good is because it is OK when she cannot make decisions. To remove it would mean he would have to go to court to get it when she became unable to answer for herself.

Thanx! That is what I thought. He has not told her yet, just me. The reason a DPOA is good is because it is ok when she cannot make decisions. To remove it would mean he would have to go to court to get it when she became unable to answer for herself.
As far as I remember from when I had DPOA for my uncle, he would have had to sign and get notarized a short statement that he rescinded my powers. I can find out for sure, if you wish.

Did you tell him she has plans for her car? If so, what did he say in his defense?

She should replace the POA with a limited POA that specifies that it only takes affect if she is incapacitated.

From eHow.com --

At any time, however, an individual can revoke their power of attorney. Notice must be served on the "agent" conveying your desire to rescind their "power." The change is effective immediately upon notification of the "agent" and anyone who may have come in contact with them in their capacity as POA. Prevent any further use of the "agent's" power by retrieving and purging all copies of the power of attorney documents. It also is important to publicly record the revocation of power.

ScottGem's suggestion about rescinding the DPOA and making it a situational/limited one is a good idea.

A Power of Attorney is suppose to be doing what the person wants, only signing when and if the other person can not. They have no right to go against the wishes of the person being signed for.