The best thing you can do is talk with your wife. Set aside specific times for togetherness... do you both enjoy reading quietly?... watching tv or movies?... cooking?... talking and sharing incidents of your day?... puzzles, either word or pieces?...
You, and she, must understand that there will be times when one may wish to sit quietly while the other feels a need to be active. It should not be construed as "I-don't-want-to-spend-time-with-you" it is just an energy issue. I don't share Kenny's enthusiasm for the motorcycle (I have health concerns myself that prevent me from truly enjoying the 'cycle hobby), but I have helped him dry it or I sit nearby in a chair and keep him company while he works on it or on the 78. Perhaps you could put a comfy chair in the garage so she can join you. ...or you could ask her if you could bring the vette inside to be with her.
She could be feeling very insecure because of her infirmities and what she can and cannot do because of them... I know I went through it with my own health concerns... but my husband assured me that he married ME. Not the things I can and cannot do.
Good luck, communication is key.
Heidi