[Adam]

If it's set up as part of a salary package, the payments (rentals) would most likely come from pre-tax salary, meaning that the car is paid for, tax free. That's how it works here in Aust, and I doubt it's much different for the USA.

Typically, leases are better geared for a predominant business usage or complete business use (ie company-funded car). Usually, whatever percentage of business use is claimed is proportional to the percentage of costs that are tax deductible.