If you had to lose a limb or a sense...

[hbelkins]

I would think it would depend on how well you could control a prosthetic limb and where you lost the leg.  If the leg was lost below the knee, I could see a manual still being viable after a period of adjustment.  All the way to the hip, though, and it would be a lot harder.

My dad was above-the-knee, but he managed when necessary. Granted, though, he didn't drive Mom's car very often.

I had a boss who lost his right leg below the knee while I worked for him. He was able to drive again after an adjustment period.