Since i have not watched all epi yet, only watched Sinal videos after their marraige.
As far as i remember, it is the same car which has been atleast thrown 3 times.
1st was night when Kunal supposed to take entire family to dinner with Viks driving that car.
Sinal are asked to come separately as a way to let them get closer.
2nd time was with Kunal driving and Siddhi, Raj and gaurav trying to get to the place where Raveena was getting married to Rohit
3rd time was recent where Gaurav is driving with Siddhi and Raj rushing to get to court to bail out Kunal before they close for weekend.
Each time diff driver. Seems when they are in a rush , they happen to have a car magically at their disposal. Rest of them they are always in financial trouble and travel by rickshaw , bus or train.
Even that car is shown to be parked outside their house.
e.g If u see yday scene of W with Siddhi, when Kunal was being tken by police for this fake rape charge or the day siddhi was leaving home after seeing K with W that night supposedly rape happened.