While we're in the process of correcting stuff
The Skyline's been a twin turbo straight six for, well, ever. That's just one example.

Of course an increase in power will increase your top speed, top speed in a car is defined mostly by the power of the car to overcome drag. I have never driven a car (and I've driven lots) that has topped out at the rev limiter.
(Mr_Kipling_, Fri 20 Aug 2010, 13:42, 3 replies)

And
The Mazda RX7 had sequential twin turbos plumbed onto its two rotor engine.
(Kyzia was here on, Fri 20 Aug 2010, 14:50, closed)

True, I'm just deliberately being an arse here.
Although, it doesn't make much difference to top speed, much more to acceleration. Small car gearing does take you close to the redline in top IME.

Anyway, given the rate of increase of air resistance with speed you need an epic power up to seriously alter anything at the top end.

The skyline is a twin turbo, yeah, but one per 3 cylinders, similar to the 300ZX system but on a striaght 6. I wasn't really being clear but I was differentiating between twin and sequential turbos really. Poster below is right about the last generation RX-7, it was the first sequential turbo production car I think, I'd forgotten that. But that engine was witchcraft.
( the mighty badger Aphrodite, on a bar stool, by your side, Fri 20 Aug 2010, 16:38, closed)

cars topping out at rev limiter
the skoda pickup normally aspirated 1.9l diesel will merrily accelerate to ca. 150 km/h at which point the rev limiter kicks in.
this is due to a shorter diff gearing compared to the hatchback base meant to increase power off the line at the cost of top end.
(Singularity was tiny but amazingly dense on, Wed 25 Aug 2010, 2:08, closed)