Travelling around in 4 continents, I have already experienced everything about uses, here and there having to wear several accessories to respect the local rules.
Well advised, we all dressed shirts with sleeves and trousers to visit the Grand Palace. But...
My wife was wearing open shoes, and part of two fingers could easily be seen. Impossible! So, to enter the Palace, she had to buy and wear a pair of socks. Cheap, as a matter of fact. And, this time, no one took the shoes off.
Check your schedulling
There's no chance to program a local trip by car without two or three hours of tolerance.
The traffic is always jammed, and the pollution very high.
We took a taxi for a five kilometers ride to a restaurant, and were forced to use the highway (extra payment) to do it in less than three hours. If possible... walk (get yourself a mask, as most locals do)