Murciélago does mean bat, but Lamborghini actually names most of thier cars from famous fighting bulls.

Murciélago was a famous bull from Joaquin del Val di Navarra's farm, partly responsible for the fame of the Miura breeders.
On October 5, 1879 he fought in Córdoba, Spain with Rafael Molina Sanchez, "El Lagartijo." He went after the picadores 24 times, with a rare courage. For this display Murciélago was spared the usual fate of death in the arena. He was given as a gift from El Lagartijo to Don Antonio Miura, who mated him with 70 cows. His line, now called the Miura line, still exists and is famous for its ferocity and courage.
The Lamborghini Murciélago, a high-performance sports car, is named after him.

 

Wow... Can't believe I missed this one... Ummm... Keep the Batman sign on the real Batmobile... Or on your belt...