Google knows that it has a lot of work to do in getting people to fully trust its vision of self-driving cars that have only a start and stop button . According to a report by KPMG, an audit, tax and advisory firm, respondents in focus groups ranging from Los Angeles to New Jersey almost all expressed a need to be able to take control of the car at any point — partly because they didn’t trust the self-driving technology and some still wanted to enjoy manual driving.