NOTE: I've only included the remixed parts, you'll need to dowload the rest from Ecaroths Wagons further down in this text.
Also to note is that Thingiverses attribution system is fucked. that's why the parent things aren't currently shown in the Remixed From section.

The Valtz Autocarriage is a ramshackle design of automative steampunk technology and guns blazing gatling gun action.
It passes through inhospitable terrain, weathers dangerous attacks, and carries its passengers safely to their destination or into battle!

No horses means that you'll only have to worry for yourself when the dragon breathes its baleful fire, and not worry about getting stuck without transport!

This is a remix of
https://www.thingiverse.com/thing:3267467 (Wagons - Dragon Hunters. By Ecaroth)
https://www.thingiverse.com/thing:150113 (Gnomedozer. By DutchMogul)

The gatling gun can be added to the normal wagons without any modification.
I've removed the harpoons on the side of the normal ballista wagon.
As well as added parts from DutchMoguls Gnomedozer to the Drivers wagon, and added a few bits and pieces myself to the aforementioned to make it "Driveable"

The tracks are close to the original, but have been cut slightly to better fit the wagons, so you could have tracks on all the wagons if you'd like.