Measuring distance from behind of car window

I am trying to measure the distance between the sensor and any object behind the car window. I thought using a laser light might work and picked Adafruit VL6180X instead of ultrasonic distance meter. However, laser beams of VL6180X can not pass the window and It measures the distance between sensor and window. Do you guys have any other suggestions?

However, laser beams of VL6180X can not pass the window

Yes it can.

You are just getting a reflection off the window and the sensor returns the closest value it sees. Try and put the sensor chip right up against the window, in contact with it.

Please make a video when the object behind your car window is a police car.

Paul

Since the VL6180X has a range of 100 to 200mm at best, it was never a contender.

Perhaps you meant the VL53L0X ? That has a range of 1.2m apparently, better but probably not enough? You'd have to mount it externally and protect from the weather, might be tricky.