Leases are based on an agreed upon set of assumptions, like how many miles you plan to drive per year, or more importantly to have accumulated when the lease is up. The idea being that the lessor has some notion of what to expect back and from that, develop a residual value number.
Typically if you do anything to the vehicle that could adversely affect it's resale value at term, you might be on the hook for difference. Some things, like high mileing it, have known consequences, a sunroof, who knows? My gut tells me all they do is a walk around to make sure the metal looks age-appropriate and check the odometer, but if the inspector on that day happens to be Nosey Parker...
I'd fully disclose my plans, in writing.
