The Hachi-Roku, I can understand... (though I don't agree with the reasons you stated for it being over-rated...) but the Z?
The Z?
A car that gave people Porsche performance for peanuts back in the 70's?
A car that proved successful in American TransAm racing circles, clinching championship wins?
A car that is regarded by many...
outside of Japan... to be one of the finest sportscars of the 70's?
Don't confuse anime-mania with being "over-rated"... I doubt many people outside of the geek-club know about Wangan Midnight (I've got the full first season, so, yes... I am a geek)... but how does a car being featured in an anime equate to it being "over-rated?"
Well set-up "Samurai" are rare at shows, and they still catch my attention every time I see them... The 240Z and 260Z are excellent platforms for further modification, as the L-block is pretty stout, and an RB or even V8 conversion isn't difficult on these cars... though the RB is the more proper engine, being the successor to the six in the Z.
It's a wonderful little sports car... and thanks to its propensity to rust into kibbles... you don't see tons of them anymore... making those that are still running quite valuable...
Oh... and going back to said anime... it's an interesting exercise in tuning... showing how, basically, a 1970's car with a fully modified suspension, a ton of turbocharging and a seam-welded chassis and rollcage can survive high speed thrashing... barely.

Much like Initial D, which is basically drift-school in CGI, there's some real nuggets of wisdom in terms of tuning mixed in with the ridiculous story and action in there. Doesn't save the series from being a gratuitous ode to illegal Wangan speeding, but there's actually very little they get wrong in the show, tech-wise.