[Geof3]

I use this. Plugs into the lighter and gives you temp and volts... usb charger as well. Many different options of the theme. Just be sure to pull it out or it will drain your battery after some time.

https://www.amazon.com/IZTOSS-Universal-Cigarette-Thermometer-Temperature/dp/B014MCRPT0?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ipad-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B014MCRPT0