A lot of people seem to have a problem with vehicle spawning, they use spawn mods that don't show all the vehicles they have installed, they can't enter or use debug mode etc. Here is a simple guide on how to spawn any vehicle that is properly installed.

Open the Steam client and navigate to Project Zomboid page.

On the right side you will see a cogwheel (Number 1), click it to show the setting menu and click on the properties (Number 2).





New window pops up and you enter -debug in the input field at the bottom (Number 3) and hit the x to close the window (Number 4).





You have the debug mode enabled, now let's fire up the game.

Now that we are in game, we will first check that the mod is enabled for use in our save file.

Click the load button, select your save file (Number 5) and check if the mod is listed as active on the list (Number 6). If it's there, good for you, click PLAY, if it's not there, you will have to enable it.





Click the MORE... button at the bottom, and then click on Choose mods... (Number 7)





New screen will show you the list of installed mods, choose one (or 36) you want to enable, by clicking the enable button (Number 8).





Now go back, the mod should be in the mod list, hit PLAY!

OK, so we have setup the steam settings, game settings, it's time to finally spawn the vehicle.





This icon on the left edge shows us that we are in debug mode now (Number 9). Good stuff!
Your mission is to find any vehicle now, and by any I mean any, good, bad, modded, vanilla, burnt... whatever.

Since this is a guide and I can cheat, I have placed a rust bucket right there on the left edge of the screen but you will have to go search for one actually.

After you find any vehicle, right click on it and choose [DEBUG] Vehicle > Set Script > and choose from the list of available vehicles, every vanilla and enabled mod vehicle will be here.





In our case, we have enabled 67 Commando and we want to spawn it, so we click on it's mod id and it will replace the vehicle we had before.

If you want to continue without debug mode, exit game, delete -debug from steam properties and start the game again and enjoy your new vehicle.

That's it!

I hope this helps, I get a lot of questions about this and now I will just point people here instead of writing walls of text in mod comment sections.

Debug mode is full of cool stuff, explore it, maybe it will motivate you to start making mods.

Tip 1: Vehicles will spawn in random colors/textures every time you replace a vehicle, so keep replacing them until you get a texture you like, for vanilla vehicles you can use the color sliders in Vehicle HSV UI

Tip2: This guide was made before some handy and easy to use tools were made, you can use bikinitools to spawn any installed vehicle, change it's skin and many more stuff, in singleplayer and multiplayer.