Usually when we drive the cars on the road, it's for a parade or something similar. It's all for show and the city has agreed to it and has made adjustments to cater for the event. GT4 cars are much closer to their road variants than GT3's, but I can't imagine it being any different.
Nobody is going to be impressed that you drove your car to the track, because there's absolutely no benefit in it. That's like a fashion model wearing the designer clothes all the way from home to the show whilst everyone else changes in the locker rooms. What's the point exactly?
McLaren obviously must have a reason for this. Some people have more money than sense when it comes to cars and motorsport. These are the most likely buyers of this car. Again, doesn't hurt to have options - surely doesn't effect me in any way.
If you're driving cars for the sake of posing infront of people, you shouldn't be driving one in the first place.
All I am stating is, history has done this on numerous moments before. Driving a racecar to the track, and back. It may not be for you, so be it, but there are gentleman drivers who would be keen on that experience, and motorsports is largely made up of gentleman drivers, that would be an interesting demographic to target such a car for.
Porsche 935's were on occasion driven on public roads to the track, despite being some of the most competitive advanced racing cars in its early years.
Even James Cameron Glickenhaus himself has repeatedly expressed through the decades how his vision is designing his future competitive racing cars to be driven on public roads to the track and meet your team there, and having minimal changes done to them on location to be in full competitive spec, i.e tyres, exhaust.
And potentially saving on transport truck costs.
Here we see an SCG 003 racing competitively on the circuit, and a competitive car it was, it has been driven on the public road to numerous racing venues throughout its career.
But is this all practical? Of course it's not. But when you're a gentleman driver who can afford all this in the first place, you wouldn't be doing it for the practicality of it, but the unique experience as a whole.
This is why gentleman drivers do all this in the first place, for the experiences. If they were thinking only on being practical, they wouldn't be racing in the first place. But they have a passion for driving, and thats what matters.
For some, it amplifies the personal experience of actually truly owning said car, to own it and experience it on any public road, and any race circuit.
You could go as far as asking those at DragWeek why they drive their ProMods hundreds of miles towing trailers to numerous locations.
Do they do it because it's practical? Or because it's "cool"? Or perhaps for "street credit" as someome previously stated.
All this, I doubt.
I'm sure most of them do it because they can, and for the experience of it, for the hell of it.
Do they have to? Of course not. But they choose to, and that's fine, we all have a choice to cater towards our preferences.
Why have people traversed accross the antarctic on foot? Why was everest climbed and topped? Why does the Bobsleigh exist?
I'm pretty sure arctic adventurers dont look cool when they return home either.
(excuse the cheap pun)
It doesn't need to be practical to have a reason to be done, they were done for the hell of it, for the experience, perhaps even the uniqueness of it.