Will the bra for the non-hybrid Highlander fit the HiHy?

Probably.

Bras are generally considered not good for cars. Yeah, they look cool and help with bug splatter, but they cause the paint to age unevenly. Also, dirt gets trapped under them and scratches the paint. Unless you wash your car frequently and take the bra off every time, you'll do more damage than if you didn't use a bra.

I tried the LeBra. It was made for regular Highlanders. While it does fit, it's missing the hole for the HiHy's additional cooling slot. I suppose you could cut a hole yourself. Otherwise, try to find one specifically for the hybrid.

I have a "clear" bra. The 3M film of a thinner guage than the film on the lower corner of your rear doors. It's very expensive but I like that it's zero maintenance (wash and wax as usual) and no one notices until I tell them about it.

Gee, I have enough trouble getting the wife to take her's off. Why would I want to put one on the HiHy... it looks sexy too....