What's the best way to leave the car everyday after work to improve the life of an automatic transmission box? Or whatever is healthy for the trans box

(1) Drive mode, park the car, Neutral mode, Switch off the ignition (keys), then once all the engine sounds have stopped - Park mode

(2) Drive mode, park the car, Park mode, Switch off the ignition (keys)

(3) Drive mode, park the car, Neutral mode, turn off the engine and leave in neutral mode

(4) other methods?

4

4 - just install a decent trans cooler and service it every 20-25,000 ks

put it in nueatral rev to 5000, kill the key and slam to reverse.
I couldn't help it, but as above said.

yeh trans cooler.
and i've also been told when in stop start traffic have it in third. so it doesn't grab fourth and lock the torque converter unnecessarily.

Definatly service it every 20,000kms but id suggest u get a full flush of trans and converter which will cost u $300.00 tops then after service it every 20,000kms.

Dont forget if u warm up ur car every morning it dosent mean ur trans is warm as its only the engine that is, so for the first 3-5kms keep the rpms under 1500rpm till its warm.

Trans cooler is also a great idea so get a large unit and place it where its gona get max airflow as it has been proven that factory radiator does a good job cooling, but when they brake and mix trans and water in ur trans then ur screwed and need a rebuild.

I went other way and replaced radiator with a large core from ADRAD and keeps my car super cool and trans as well, even my radiator bloke said it looked like a great unit and he didnt know about it as i traced it down through the ADRAD rep.