2020 will be the final model year for the Ford Mustang Bullitt, which will be replaced by a new special-edition Mustang for 2021. Seeing a camouflaged Mustang Bullitt prototype testing on public roads with Michigan number plates leaves us wondering whether the Blue Oval is already working on its replacement.

That’s our best guess for the test car you’ll see in the gallery attached below. While it has many Bullitt cues, it’s most likely the upcoming Mustang Mach 1, planned for launch just in time for the 2021 model year.

Gallery: Ford Mustang Bullitt spy photos

The most obvious changes are going to be at the front where the entire fascia is disguised, suggesting tweaks to the grille and lights are in the cards. The bumper appears to be slightly reshaped but we can’t confirm it’ll have a new layout at this point.

At the back, this prototype looks very similar to the test car we spied in March last year. However, Ford is now using what appears to be a redesigned production bumper with modifications down low for testing gear on the exhaust.

Interestingly, the company seems to be using components from different trim levels and special-edition models for this trial car. The multi-spoke wheels, for example, have a Mustang Pony Package look, while the window trim matches what the Mustang Bullitt currently offers.

With all that said, it’s difficult to predict what exactly is happening here. Still, our educated guess is that this is the upcoming Mustang Mach 1, which should bring performance upgrades over the Mustang GT upon which it will be based.