This looks similar in some aspects to the Liberty Walk Bodykit but it is a different design entirely.
This is produced by the Chinese Bodykit Designer MBYTE and was originally intended to be a One-Off called the “AntiVirus” for an Influencer but has entered production and can be purchased.
The Maserati Gran Turismo is definitely a cool car but it’s remained the same for all iterations of Forza and hasn’t really had any cosmetic variety at all outside of Forza Aero and thus would benefit greatly from a Bodykit of this type.
If MBYTE have a Website then I can’t access it unfortunately due to it being in China but here are two International Articles on it.
You can unironically purchase this Bodykit on AliExpress
https://m.aliexpress.com/item/1005002960192945.html?gatewayAdapt=Pc2Msite