Don't worry about this, he'll come around. It's just that he must still be in mourning for his darling dream......of driving around with the wind whistling through his hair and lovely young ladies smiling at him...with men, reality doesn't seem to set in till old age is staring him in the face. Just remind him you love him..and remember, always smile at him when he comes home and love him. That's mostly what men need and want. Love.
As soon as he comes to grips with his loss, then start telling him how nicely he can do the garage...no, you said he was not a handyman, so keep reminding him how smart he is and how you love HIS idea of selling the car, and how smart he was to get a house with a big garage that could be made into a sewing room so he can watch TV in peace and quiet, and actually hear it.
Think that would work? It used to with my own DH.