Rotate object towards a rotation? Any Advice

Unity Engine
1

I have a game where I drive a car with an add force

problem is if the car points up, it flys into the sky.

In order to fix this, i want to check if the car is grounded (done) and then if it is not grounded, smoothly rotate the car to be facing downwards, so you cant fly off forever.

    if (isGrounded == false) {
//what do I write in here to smoothly rotate my car so its facing another rotation?
        }

any advice appreciated!!

2

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