Hi Charbel,
I wouldn't necessarily change the front headlamps, as the car was intentionally designed with the larger emphasis on aerodynamics, displacing the overall design somewhat, which of course is in the shape of McLaren's swooping chevron. You could elect this part to be silver or differentiated by another colour, but when you evaluate the array of your images, the front view looks very good. Because when you take a deeper look, you can see the headlamps and see how this area was constructed. So this has been done well.
On the rear, the real-life car has a unified bumper, but we can all understand if you've exhausted all possibilities to somehow make it as one plane across, then that's ok. Because the rear diffuser is highly detailed and one of the model's best features.
The replication of the Monocell II carbon monocoque is excellent. The side, front and rear view should make you feel the design overall is faithful to the real-life car. If you can keep sloping more of its side panels perhaps, or more improvements if you feel it's required, that would be great to see. But these technic-based models will never be able to honestly fully capture the natural undulation of the model you're basing it on. The P1's rear is too severe compared to the 720s, since the former is a hypercar, so what's an advantage to your model is that it's easier to streamline.
I'm not a technic-based enthusiast but this is by far, the very best model build I've seen thus far, from anything I've seen from official models, to other user-based customisations. It's hard to already build it, but the final result might inelegant in Lego. It has the facade to be an official set...