Some tips to avoid honking from cars that I found that work:
1. Wear a helmet. You will look like a "serious" cyclist and not just some road-scum-thing which would cause the car driver remember his last gas and insurance bill (which got raised because of a cycling related accident).
If you want to make use of your right not to wear one, wear a cycling cap.
2. Look as dodgy as possible. Think "Charles Bronson", "50 Cent", "Snoop Dogg" etc.
3. Never be clean. Wear oil-smudged track pants, ripped clothes. Extra points for blood stains.
4. Did I mention to not look clean? Add some dirt from your flower pots to your face and clothes before you ride.
5. Do wear lycra (as dirty as possible as mentioned above). Nobody wants to f@ck with a hard core multiple watt leg powered dope-fiend. Extra f@ck-off points for lycra which advertises products like motor oil, car related companies, something cycling related or a chronological date. Double points for Japanese lettering.
6. Do use lights. Try to look "nice about them" but make clear that your lights -are- able to cause seizures in a 500m radius, but your are not doing that "to be nice".
7. Do not try to appear "political", "romantic", "rational", "smart", or "hipster" about your riding. Bullsh^t like "I have the right to use the bike on the road etc". Look more like "F@ck you - and your whole crew - and car". Also (even though hard to do) try to look like you have a Porsche on your garage.
8. Never react to honking when you know that there is nothing wrong with your riding. Be calm and try to make the other guy think that you think that he is insane. Motorists do have to go through medical checks.
If it is your fault, try to look like "sorry man but I just crashed on that race and I think that my brain don't work that well no-mo..."
9. A few visible scars are helpful if you have them. -Do not cause the scars your self!- The bike will probably provide them for you sooner or later.
10. Have a piece of carton with a number on or a proper race plate on your bike. Extra f@ck-off points for numbers like, 13, 23, 666, or round numbers like 500, 300 etc.
Pro - tip: If you do not want to go for lycra, go for the "Drunk Peasant" look. Smudged overalls, A mysterious container on you or the bike.
Good luck!
For illustration purposes only: