Those are some tough questions, which I assume are rhetorical. Have your tried talking to your neighbor about this problem? This can be a form of disturbing the peace, which is a violation of the city’s code, if so, your next step if the neighbor doesn’t correct it is to call the city code enforcement office and ask what your options are.
I was hoping someone familiar with Tundra’s would know what causes it. Maybe an anti-theft system gone bonkers? Key fob- if they have them- left inside?
I’m not familiar with the Tundra, but it does indeed sound like an alarm system on the fritz. Sometimes I go for a short walk at night around the block before retiring, and there’s one car parked in a driveway that always beeps at me and flashes the lights as I walk by. It must have some kind of motion sensor alarm. On that one anyway, it only beeps and flashes once or twice, just for a few seconds.
There may r may not be a problem with the car. But there IS a problem with the owner.
First you gotta get the owner to care. Then the car can get fixed.