
My eldest sister once owned an EH Holden (classic old Australian car) and a Kombi van and driving these cars required the two-fingered wave. When driving the Kombi/EH and passing another Kombi/EH owner, index and middle finger were raised from the steering wheel, acknowledging each other's coolness factor or sympathy depending on repairs and rust said car had. The slightest head nod was also thrown in, very discreet and completely hilarious.