With an auto security system, you are shopping around for a local shop that does good installs more than what brand the alarm is. If you are buying the alarm to prevent the vehicle from being stolen rather than just for the convenience features, I highly recommend you do not attempt the install yourself. Even if you are pretty handy, an amateur installed alarm can make the vehicle easier to steal than one without anything. This is something worth paying someone who knows their stuff.

Once you find a reputable shop, it doesn't matter that much what brand they sell. If they do actual good work, they are most likely not selling junk. But you can't really go wrong with Viper.

Wyze sells cheap but decent quality security cameras with good alerts. Probably not the best privacy tho, so I wouldn't point them anywhere too private.

Edit: Source: I installed car security systems for ~15 years.

Viper has a pretty good 2-way alarm (your key fob alerts you) and most of their models have relay contacts for fuel pump kill or start signal kill.

I found a budget version made by Avital I've been using for several years.

people are starting to catch onto my patterns and hover around my vehicle like vultures. Please tell me the best security system you know of.

A free first step would be to have no observable pattern. And/or leaving that general area if possible.

I would think about the actual threat model and what I could do about it. If someone steals your doodad with an airtag on it are you going to find it and take it back from them?