Reddit mentions of Ecologic Mart Book Light - 3 Colors x 3 Levels x 2 Heads - Portable Clip On LED Lamp for Reading in Bed - Rechargeable 1200mAh Battery - Warm, Natural and White - Music Stand Light (No USB Charger)

Another user has laid out most everything you need to know. One thing I would suggest is to make sure you're sleeping on a flat surface. I slept in a Volkswagen Golf for about six months unable to fully stretch out my legs or flatten out my back and it really took its toll on me physically. That shit will hurt you in the long run; don't think you can just power through it. If you're waking up every morning with your eyes burning and need massive amounts of caffeine just to stay functional, you're doing it wrong. By the time I upgraded to a Dodge Grand Caravan, the damage had already been done to the point where I'm not sure I can fully recover. I actually went to Home Depot to get a composite hardwood board cut to fit the floor of my vehicle. Before that, I'd been stuffing all sorts of things under my mattress to even it out. Don't make this mistake; it will not work. You need a level surface for decent sleep in long-term situations. If you don't have enough space to lie down completely flat, make changing this your priority and do the best you can.

Check the weather every night to gauge temperature in your area. It sucks waking up because you're too hot or being passed out all night just to realize in the morning you've been freezing your ass off for hours. Don't park under trees, if it rains the water will collect on the branches and fatter droplets will wake you up several times throughout the night.

Get car shades like the other user suggested. You should be able to pick up a universal one at most auto supply stores. Related to that, it might be a good idea to keep some maps/brochures, thin cardboard, or thick paper around. No matter how well you're covering up your windows, some light will get through a crack somewhere and it's incredibly annoying to position yourself in a certain way just so a streetlamp isn't shining a light in your face. Don't worry about people passing by to see you potentially sleeping in your vehicle. The vast majority of people aren't really paying any attention, and the ones that do spot you don't give a shit.

Showering before you sleep each night is a good idea. Small enclosed spaces will build up odors much faster, and you should try to avoid dirtying up your mobile home as much as possible.

Watch for mold. Breathing all night in a vehicle will cause moisture to collect on your windows among other things (unless you crack a window, but then it's loud). Wipe your windshield whenever possible with a towel/paper towels, and check for mold routinely. Always take down your car shades in the morning to prevent mold growth. Sunlight does this pretty well all by itself. If you're using a mattress, it's not a bad idea to spread some desiccation packets underneath to absorb moisture.

Look online at crime rates in your area to select a good neighborhood to park in. Street parking in a not so densely populated residential area is best, as you're on the street but safer than being completely isolated in some abandoned alley somewhere. It might take some time to find a place to park at, but that's just what you need to do. I rotate my car on three relatively quiet streets throughout the week for street cleaning, and to not get towed due to the 72 hour law in my city. It's a nice area to pass out, save for the occasional annoying driver that likes to hit 50mph going down my block.

Once every few days, drive your car around for fifteen minutes. That's your home now. A dead battery is not what you want.

Don't drink any water past 6:00 pm. Needing to go to the bathroom at night with nowhere to turn blows, and peeing on the street makes you feel terrible. After a while, your body will condition itself to pee at the time you've been routinely going at.

Get a library card. It's kind of awesome to read in your car with all the shades up. No distractions, and all the stories you have time for. Good for mental health, and you're improving yourself while being entertained. Grab a rechargeable reading light to use for nighttime adventures. I used this one until I eventually upgraded to a Kindle. You can also wash up in the library bathroom if you can't get a gym membership.

That's all the things I can think of at present. The most important thing is to stay healthy, both physically and mentally. If you're tired all the time, change your setup and don't stop until you can get it right. It's tempting to just lay down and ignore being slightly uncomfortable, but all that builds up until you can't stand it anymore. As for mental health, just know that this isn't permanent. Save money where you can, and keep working to better your circumstances. There's nothing wrong with car living, it's just different than what most people are used to. Beats paying rent, especially in my area.

I hope some of this helps. You can do it.