悠闲自得

wǒ què xìn tā cǐ kè zhèng yōu xián zì dé de kāi chē xíng shǐ zài gāo sù lù shang

我确信他此刻正悠闲自得地开车行驶在高速路上。

I'm sure he is tootling down the motorway at this very moment.