Lease cars have mileage restrictions and you are held responsible for those mileage overages. Instead of getting a lease car that you think you will run high miles on, consider purcahsing a reliable car that you can drive as many miles on that you wish. Reliable cars dont have to be new and expensive, there are plenty of CPOs out there that are great vehicles and will give you the flexibility that you want. Also, consider the type of financing. Residual based finanncing may be a good idea as long as you get a loan with a buy back provision (some credit unions offer and fiwize.com has them too). You own the car, pay down the loan down until the residual value. Then you decide if you want to keep the car (and pay the rest)...or return it with the buy back. Check the mileage allowance on the buy back provision to make sure it works for you. Good Luck!
Got it.. you should be able to avoid the mileage surcharge if you buy the lease vehicle (they do surcharges for covering their resale). Remember you don't have to finance the new loan to purchase the vehicle through your current leasing company, so shop around.