"Better" is a slippery word.
But generally a Lambo is considerably more expensive than a Mustang, which means more money can be spent on every little detail, making a Lambo perhaps a bit more overall better than a Mustang.
A little finer interior, a little more time aligning body panels, a little more time buffing up the paint, a little more time on the drawing board reducing weight etc etc.
No
corvette or a challenger
The Lamborghini
enzo ferrari is much better than a lamborghini
LAMBORGHINI is way better than the saleen s7!
Lamborghini reventon or a mustang cobra, as if luxury 300c is way better and ssc-ultimate-aero
Is 50,000$ better than 500,000$
the lamborghini murcielago looks way better than the adui r5.
speed & looks
I think Lamborghini is better (especially the Murcielago model) because it has better looks and styling than Bugatti, but in case of speed, Bugatti is better.
It completely depends on how you define better. Aston would be better for style, reliability and comfort but the Lamborghini would beat it more often than not on the track.
It depends on many factors, but it is not necessarily better.