How to effectively play light tanks/vehicles

Hello,

I have seldom grinded light tanks in medium/high tiers.
Could you please explaint to me how to play them usually?
They have thin armour and I always get destroyed, even though they are fast.
Sometimes they have sub-ammunition and can hardly pierce any armour.
They are good to capture spawn points, but otherwise I don’t know how to play them.
For example I will soon unlock the Russian BTR-82AT.

That entirely depends on vehicle and needs to be judged on case to case basis. Some vehicles are light tanks in name only.

For example I wouldnt play 2S38 the same as I would play the Vilkas.

Light tanks arent really “the” thing anymore, especially since Gaijin has stated they are going to focus more on CQC maps in the future. Making maps more tinier and adding more redzones.
Thus removing the flank on purpose.

Always flank flank flank. If you can’t if it’s a city map or small map, then stick behind heavies or mediums with more firepower and armor. Scout for those blind german mains and take out enemy’s tracks and barrels. Win the game with assists.