The scooter driven by Ash is an iconic Indian 2-wheeler called Kinetic Honda. The model shown (ZX), however, came out in late nineties, while the film is set in the 80s.
When Naman and friends are drooling over picture of a naked woman in a magazine, a post office is visible in the background, with a modern logo which came into being only in 2008 while the movie is set in 1980s.