Ist das in Zeiten von Omikron tatsächlich noch so, also du als negativ PCR Getesteter mußt in Quarantäne weil ein Mitfahrer im Fahrzeug positiv getestet wurde? Hast du dafür eine Quelle?
Hier eine durchaus verlässliche Quelle:
Guidelines for international travellers in March 2022:

PCR test no more than 72 hours before departure

PCR test on Day 0-1. You must wait in a SHA++ hotel for the results

If test positive, receive treatment in hospital for 10 days. If mild or no symptoms, can stay in hotel or hospitel

If you test negative on Day 0-1 you are free to travel

On Day 5, do a self-ATK test and upload results to Mor Chana app

If positive, receive treatment in hospital or a hotel/hospitel for those with mild or no symptoms

Tourists can call 1155 or 1672 for help
High risk cases who had close contact must do 7 days quarantine in a designated hospital/hotel isolation facility + 3 days observation. Including two ATK tests on Day 5-6 and Day 10 after close contact. See below for those who are considered to be high risk contacts.
High Risk Cases:

Those who do not wear masks during close contact with an infected person

Near or talking to an infected person within 2 meters and for more than 5 minutes (sick person was coughing or sneezing)

In an unventilated place for more than 30 minutes

Sitting next to infected person, on left or right, in airplane or hotel transfer, or have close contact with someone within 1 meter without wearing a mask for more than 5 minutes.