many times ive seen the Audi courtesy cars at VIE, stationary next to the bus boarding or on tarmac waiting for incoming passengers. The welcoming car has a driver but he's not holding any particular signs for pax info.

Who is it meant for? M&M HON traveling intl C/F?

I've done LH and other alliance F flights to/from VIE and have never been offered a car transfer there, except from LH at their hubs. And obviously OS does not offer F service