Air conditioners cannot work with the car's engine off.
The film shows a typical police/crime news being shown in the morning through the afternoon with the same host. A program like this would never take place on a morning schedule (as shown in the first minutes of the film) due to government regulations that forbids such shows - although that kind of crime news can be showed but it's always along with other types of news and information; and no host of such shows would occupy two different schedules with the exact same program as shown in the film.
It is not explained how Djalma never tries to shake up the car from inside so the passersby can notice the car moving. Also, a vehicle parked on the same place for several days would generate suspicion on the neighborhood.