The strategy has worked so far, winning a critical first approval in the Netherlands that cleared the way for a Europe-wide vote expected soon by regulators from 27 European Union countries. Seven other EU countries, including the Czech Republic, Belgium and Denmark, have granted Tesla national approvals for the driver-assistance technology, which is not fully autonomous.

But Tesla’s campaign is built on faulty company safety research that can’t support the company’s claims to officials or the public, according to seven traffic-safety researchers who examined its methodology for Reuters.