Requiring almost half a million bricks and months to build, the car will be on display throughout the show inside the Microsoft Theatre - Xbox’s home for all activities for the show.
In total, 467,854 individual 'bricks' were used in its construction - 200,000 more than what was used to construct the 720S model in 2017.
Teams of 10 model-makers worked in shifts around the clock and took 2,725 hours to 'click' all the pieces together - some nine times more than the real hand-built Senna (300 hours).
Including design and development, a total of 4,935 hours went into creating the model, involving 42 individuals from the Danish toy production company's build team.
Also announced at E3 - Lego fans will be able to live out their ultimate McLaren fantasy thanks to new downloadable content.
As part of the Forza Horizon 4 Lego Speed Champions expansion, the McLaren Senna Lego set will be fully playable in-game, with players being able to explore a new Lego-themed world, complete with new challenges, races and even an entire Lego city.
Forza Horizon 4 sees players explore a stunning microcosm of the UK, with changing seasons, dynamic weather and some routes - all in native 4K and HDR.
First announced at last year's E3, the game features the McLaren Senna as its cover car, which is also playable in-game in non-brick form.
The game launches worldwide on June 13 on Xbox One, Windows 10 PCs and Xbox Game Pass as an Xbox Play Anywhere title with a price of £15.99 (RM 85).
However, the game is included at no cost for players who own the Forza Horizon 4 Ultimate Edition, Forza Horizon 4 Expansions Bundle and the Forza Horizon 4 Ultimate Add-Ons Bundle.
For Xbox Game Pass members who have access to the standard edition of Forza Horizon 4 are eligible for 10% off a standalone purchase or 10% off the Forza Horizon 4 Ultimate Add-Ons Bundle.