We have some close friends that lease both their vehicles. They have a Sienna Mini-van and some sporty new VW - not sure of the model. I can tell you that they get a loyalty discount for renewing their leases - at least it is positioned that way. They were both on year 2 of their existing leases this Summer, but received calls stating that the dealership wanted to reward their loyalty with new vehicles and that they wanted the existing leases because they were short on used cars to sell. My friends went with upgrades to their existing cars at no change to their lease rate. If you don't mind spending the monthly fee for the foreseeable future, then you should probably lease. I'm sure you can continue to get new vehicles at about that same rate from your dealer well into the future.
Here's why: My friends saw this as a win-win. They don't see a rate hike, they get brand new vehicles, and the dealership gets more used cars in their inventory. They love new cars and probably would have gone with leases again, so this was the right move for them. Of course, the dealer just locked them into an extra 2 years of leasing. They went from 2 years remaining to 4, and I'm sure in 2 years they will get a similar offer to lock them in again. You see this trend with phones, cable, etc....companies will give you something extra to guarantee you stay subscribed. Getting another 2 years on the lease far outweighs the risk of letting the lease expire and hoping they come back at $425/month istead of $400/month.
Honestly, if you want a new car every 3-4 years minimum, leasing is your best bet. I've never leased - I'm a firm believer that you buy the car, pay it off, then save thousands until you need a new car again. My wife and I have had both our cars paid off for at least two years now. A lease would cost us about $800/month, so we've saved just shy of $20,000 (Maybe $18,000 worst case, assuming you'll spend money on tires, breaks, and other servicing). If you want to replace your car every 6 or 7 years or longer, you're far better off buying the car and paying it off quickly. You'll net all that extra cash to do other things with in the period between your payoff and your next purchase. I think that's an awful lot of dough to fork over just to have a newer car all the time, but it depends on your priorities. Hope that helps.