I'd be happy to hold onto the Passat for much longer as it does everything that it's supposed to do extremely well. I kept my interest in my previous car by upgrading things along the way. I'd like xenons, LED tails, and a reversing camera, but the cost of retro fitting is prohibitive on newer cars. OEM Bi-xenons on my 2004 Passat cost me £100 from a breaker that didn't know what they were and they also plugged straight in and worked.
It is much cheaper to keep a car for many years, even with additional repair costs to account for. I reckoned on £1000 a year for servicing and repairs, which is waaaaaay less that the depreciation on a car in warranty. However it's the cost to change that comes as a stinger. You spend a few years watching your savings grow, then boom, one swipe of the debit card and they look pretty sick. It might be time to get out of the Passat while it's still worth something.