This guy has a trailer parked in a lot on Middlesex Turnpike in Burlington - past the Mall, just before it splits to Network Drive. He's got a couple of Big Green Eggs and grills up hot dogs, sausage, and kielbasa (along with peppers and onions). He has an impressive condiment selection - several varieties of mustard, hot sauce, etc. My lunch companion was impressed when she found the celery salt, which is one of her favorite toppings.
If you are in the mood for a hot dog, it was a tasty meal. I had the large hot dog for $5. It had a nice solid bun and was well grilled. He uses Pearl brand hot dogs. Its probably not pilgrimage-worthy like Speed's, but this area of Burlington doesn't have a lot of tempting other options, to be honest.
He says he's there usually till about 3, but with winter approaching, he'll be shutting down for the season soon. Its an covered but open sided trailer, not really that protected from the elements. I think he's had several locations this year, but finally seems settled where he is. Friendly guy doing a nice job with a grill - I'd recommend trying him in these sunny days before the holiday if you are in the area.