Rosenthal Robotics' flagship product is the Zoomer, a self-aware hybrid automobile based on the Ultra Car design. The Zoomer turned out to be a bona fide sales smash, especially once Joe fixed that little programming glitch that left drivers stranded in the Amazon rainforest.
Rosenthal Robotics is headquartered in a suspiciously (and intentionally) phallic tower located in Denver, Colorado. In addition to containing offices, labs, and Joe's ever-increasing toy collection, the building also houses the Martian Resurrection Chamber that recreated Walky and others, although this aspect of the company is almost certainly not public knowledge.
Following the events of Joyce and Walky's wedding, Joe also set up an interdimensional portal deep within in the building. Ultra Car and Leslie Bean would later use this portal to rescue Rachel from another dimension.