Google’s self-driving cars are getting some attitude. Company engineers have been working on teaching their autonomous vehicles the subtle – and often obnoxious – art of honking, according to Google’s May self-driving car report. The innovation makes sense. After all, while Google’s 24 self-driving Lexus SUV fleet are hybrid machines with a modicum of engine noise, Google’s growing gaggle of 34 pod-like prototypes are all-electric machines that barely whisper their presence. Sometimes, a short stable of the horn is required to let folks know they’re coming.