I love these kinds of threads, and I love tools
@LandLocked93 is correct, you don't see large gauge connections soldered in industry either... be it industrial or aerospace, and I like to think I spent more time than I should pocking around where I shouldn't just because i was curious.
@LandLocked93 also covered a lot of the stuff I would suggest so I will add my favorites.
I'll list this stuff out and then dump links at the bottom, but here are the things I like:
- Hakko 888d soldering iron. This thing is minty and is what all the aerospace instrumentation guys I used to work with used.
- Weller P2KC butane soldering iron for all your in vehicle soldering needs.
- Kester Solder flux core, 60/40 - This stuff improved my surface mount soldering considerably
- Soldering rosin - keep them tips clean!
- Scotch super 33+ electrical tape - it is seriously good, but not cheap. Doesn't turn into a sticky mess long term
- I like having some alligator jumper leads and a power supply (you can make one out of a computer power supply, let me know if anyone want the deets).
- GOOD multimeter - Fluke 115 is what I like, because I have a tool problem and I am single

add in some aligator test leads for bonus points
- I like to use adhesive backed heat shrink in most applications
- Electrical contact cleaner of some type is very helpful
- A third hand with alligator clips for holding the wires you'll be soldering is a must!
- I like the hydraulic crimpers for the big wires.... crimping in general is a rabbit hole... pick your budget, buy as you need.
- The knoweasy wires strippers are an Adam Savage favorite and I agree, nice to be able to set the strip length
Amazon product ASIN B00ANZRT4M
Amazon product ASIN B000WOHSHMcrid=1TRHTGAUQN59N&keywords=weller+butane&qid=1676171103&sprefix=weller+butan%2Caps%2C155&sr=8-7
https://www.amazon.com/gp/product/B000OCFFMW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B06XR8BY65/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B07WFL122J/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1