You know it is you! What a discovery! I loved it. It is everything that Rothenburg odT wishes it was, and probably was in days past.
Hills, cobblestones, cobblestones on steep hills, roses everywhere, a fortress at the top, loads and loads of half timbered ancient houses (Fachwerk), helpful TI, easy and free parking and it ate hundreds of photos.
And there's river views (the Neckar), interesting walls, (most of the walls survive).... I could go on.
It is right off the autobahn, near the junction of the A6 and A81 in the northeast corner of Baden-Wurttemberg near the Bavarian border, there is a great spa (related to the one at Erding) just down the road, and the countryside is Beautiful.
Whoever you are who recommended a visit to Bad Wimpfen - take a bow, and thanks.