"neither his car is electric" was wrong, while the hint said neither for neanche. Is this bad English?
Yes. "Neither is his car electric"could be acceptable if you had already introduced something else he owns that is not electric. But it sounds rather archaic. "Nor is" would be more common.
Can someone tell me why the sentence can't be Even his car is electric. The hint has even as the first choice. I will report that. Thanks