Inspired by Joanie, I made the first trip to Speeds. He really is easy to spot if you just drive to the Grainger's - I think his truck is towed by a Chevy Suburban.
When I was there, Mr. Speed was just hanging out in the back. The dog is enormous and it tastes a little like the "metts" my mom used to cook. It is definitely the best hot dog I have ever had, but it is not something I could eat more that once a month... ok, maybe every couple weeks.
While I was there, Jake from Jake's in JP was also getting a dog. He said that they were going to be closed for the next year - in the meantime, they would be looking for a new location and doing catering. If anyone is interested, he said you could call the old number.