Traffic is heavy all the time, especially during rush hours. Lanes are tight. Lots of ppl riding scooters and bikes. Lots of ppl on foot. Parking spaces are tiny. I really recommend the CDW! Not for what you might do to the car but what might be done to you. DON'T leave anything in your car!! Theft can be a prob in some areas.
Don't cross a solid white line coming to a traffic light! Cops will cite you for that. Watch the signs for when you can turn on red...that can get complicated. Watch for when you can Meter park. They block lanes off during rush hour. Hanama Bay for snorkling is closed on Tuesdays. I like the Paradise Cove Lu'au. Be sure to do the Swap Meet at the Stadium. Wait to do your T-shirt buying til you get THERE! Wayyy cheap! Good buys! GO Early will eat a whole day or better part of one anyhow. You must eat at Dukes at Sunset but go before then to get a Table.
Don't be afraid to Haggle on the price of anything! The beach is best at Hilton Hawaiian Village...all beaches are Public...you don't have to be staying at a hotel to use their beach! Why is it the best? Their SAND is awesome! Most of the other sand in Waikiki is Rough as h*ll.
Take a drive to Kailua on the Pauli Hwy! 30 mins. Kailua Beach is wonderful and the sand is like Baby Powder. Free parking at the park.

How's that for a quick brain dump?