Re: No surprise
"...the[se] tax breaks, on the whole, benefit the better off and are effectively subsidised by everyone..."
I agree on the need to jump start challenger industries. It is very hard to compete against an entrenched and effective product choice without both an appealing product and some sweeteners to make the leap.
The way the USA tax credit works does favour high earners because of their income tax amounts and their ability to consider premium priced vehicles. Though it seems that those high earners are also the biggest contributors to the tax base. Perhaps lower-rate tax payers can console themselves in that their contribution to the choices of the wealthier is modest. http://money.cnn.com/2013/03/12/news/economy/rich-taxes/index.html
The picture is similar in the UK with the current £4,500 government subsidy on the purchase of new extra low emission vehicles. https://www.gov.uk/government/publications/plug-in-car-grant/plug-in-car-grant-eligibility-guidance and the way the tax base is built https://www.theguardian.com/news/datablog/2014/jan/27/how-many-pay-top-rate-of-income-tax-uk