"Yes" to all three.

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Mod Manager has a feature which allows you to hide mods that aren't of interest.

RV Interior used to have two mods, a SP-only mod and a MP-only mod. The current version has a single, combined mod, built on top of the old MP-only mod (and still using its mod ID). This means that SP players who previously hid the MP-only version will not see the combined version in their mod list now.

Check your hidden items, and unhide the RV Interior mod.

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Project Zomboid tracks mods for each save, as well as the default mods configured from the main menu.

To change the mods for a specific save, click on "Load" from the main menu, select your save, and then click the "More..." button. You can then "Choose Mods" to configure the mods being used by that save.

(You can tell if the mods in a save are different to the default mods, because loading the save will cause the game to freeze up for a bit, with a message saying "Reloading Lua" in the top-right corner.)

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This message means that the vehicle_interior map is not present on your save. On a multiplayer server, it may just be loading slowly - you can say "No" to remain in the void and keep waiting (the dialog will reappear after a short time if the map still hasn't loaded.)

If the interior never loads, the most likely reasons are:

• The mod was added to an in-progress game (this requires additional steps to be taken - see the description.)
  
• Using a non-standard base map (the mod only works on top of the base "Muldraugh, KY" map, although it should be fine in combination with other modded maps that also go on that base map.)
  
• In MP, not having the vehicle_interior map at the top of the map list (needs to be fixed by the server admin).

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The interior map is, behind the scenes, just a building, and unless you change your sandbox settings, all buildings start the game connected to the mains water and the power grid. Project Zomboid has no way to indicate that certain buildings should start off already disconnected.

Thus, at the start of the game your vehicle interior may have free water and power, until these services break down.

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In the current version of the mod, there are rain collecting metal drums on the roofs of many of the vehicle interiors. For those vehicles, you can simply plumb your sink using a pipe wrench and start to use rainwater.

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Busses do not have rain collectors on the roof, as they did not have a built-in water system prior to the apocalypse. For busses, you will need to collect your own water, such as office water coolers.

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Behind the scenes, the mod uses generators hidden outside the interior maps to provide power to the building. As you enter and leave the interior, the fuel in the generator and the charge level of the battery are synchronised - fuel used by the generator will reduce the battery charge, and changes to the battery's charge (up or down) will likewise change the fuel level in the generator.

At the moment, the exchange rate between battery charge and fuel is very favourable - a 100% charged battery is equivalent to a 100% fueled generator, which can run a refrigerator and internal light for many days. Still, keeping a spare heavy-duty battery or two around is probably a good idea, so you don't get stuck with a flat vehicle battery.

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