You don't say whether the S Type is manual or automatic. I had auto's for many many years without any problems. Then I bought a manual X Type and had to spend over £1000 having the flywheel and clutch replaced. I've now got an automatic S Type and wouldn't go back to a manual again. As for DPF, you'll find that if you just potter around town all the time you may have problems. The car needs a good blast now and then to discharge the DPF and all should be fine. Now I've given you an excuse to put your foot down!!!