The Rocketcar is Seymour's latest invention. It was designed to be the first horseless carriage being power by rockets.
Seymour built it in winter 1882 so he'll win first place in the Horseless Carriage Competition, against the Germans' internal combustion engine and Stanley's steamer.
Millward thought it looked amazing, and want to take a spin on it, but was interrupted by Cavis because he didn't finished writing the script for their musical.
After the two musical writers were bonded out, they wanted to go see the Chtristmas play at St. Barts. So when Seymour showed up, Millward asked him if they can use it to get there. After the ten rockets were used up, the cucumber used the last one to jump over the open draw bridge, which resulted the car to fly over London. It landed by the chruch enterance, which catapulted the veggies out of it. Seymour might've picked it up afterwards.
It's unknown if he ever won, though.
The car is based after (or may've been) a motorcycle, with the exceptions with the passenger seat in the back.
According to Seymour, there are eleven rockets. Every one except the last one were tested. Millward used the last rocket to jump over the draw bridge towards the church.
- In the concept art, it originally had a set of wings on the top rocket and a beaker on the left side.