We had a hassle with this the last time we rented from National...and we were given two different answers on whether DH could drive the car rented in my name. If you are an Emerald Club member, your spouse can drive the car. Our problem was that I used a coupon/id that wasn't the Emerald Club code, so the counter person told me that the EC rules "didn't apply" (she was NOT a pleasant person). We made several calls after that, and we were told EC did apply. I was angry because I always make all the reservations and DH drives...but we got it resolved in the end.
We rent from them in a few days...first time since then, but National actually had the best rates for us.