This vehicle is heavily based on the 2011-2016 Lamborghini Aventador, with its engine cover design resembling the 2010 Audi R8 and it's design also seems to be influenced from other supercars such as the Vector M12 (rear) and the Vencer Sarthe (front).
Gangstar Rio: City of Saints
The Galloppino is heavily based on the 2010 GTA Spano, with headlights resembling the 2006 Lamborghini Murciélago LP 640.
Gangstar Vegas
The Galloppino is likely based on the 2003 Lamborghini Gallardo with headlights based on the McLaren 12C.
Gangstar Vegas (Updated) and Gangstar: New Orleans
Its design is based on the 2008-2013 Lamborghini Gallardo LP 560-4.
The Gallopino originally had a different rear that bears a great resemblance to the McLaren MP4-12C
In early versions of Gangstar Vegas, the Chinese subtitles refer to this vehicle as "大牛"(Big Bull) during Busting Through, suggesting its similarity with real life Lamborghini models.
The Longhorn from Gangstar: Crime City is possibly a predecessor of the Gallopino as both are based off of the Lamborghini Gallardo.