Lamborghini decided to improve on a formula that has already proved very successful for them, by combining a spyder body style with the unique characteristics of a rear wheel drive sports car.
You probably guessed by now that we’re talking about the Lamborghini Gallardo LP 550-2 Spyder which can been seen in the flesh these day at the 2011 Los Angeles Auto Show.  
Stephan Winkelmann, President and CEO of Automobili Lamborghini said that "With the Gallardo LP 550-2 Spyder, we are expanding the Lamborghini
lineup with a purist model that adds yet another dimension of driving
fun. This will appeal in particular to a very special group of customers
that enjoy a spirited driving style and also like to experience the
sheer pleasure of open-air driving." 
With power provided by a 5.2-litre longitudinally mounted V10, the Lamborghini Gallardo LP 550-2 Spyder is expected to produce 550 HP (405 kW), which from a car that weights 1,520 Kg will translate into 4.2 seconds when accelerating from 0 to 100 Km/h and a top speed of 319 Km/h.
The LP 550-2 is going to be available with both manual and automatic 6-speed transmissions, and due to the fact that this is a rear-wheel-drive model with a folding roof, that automaker has re-tuned its suspension and chassis and has also adapted it in terms of aerodynamics.

Source: Lamborghini