Hi Darran,
I have only just seen this post. Carole has already said some of the things I would have said.
Our cars are similar. I have had my s type for over 5 years now and I have never had a problem with the DPF. I only o about 5,000 miles a years with mostly shorter trips, but I do make sure I get a long run once a month so.
I use Shell V Power as there is a Shell Garage about 500 yards away, and I also use Millers Eco Plus for diesels with a shot with every full tank or so. It also cleans the EGR valves,
There is an Event on Sunday 22nd July for JOC members at Lancaster Jaguar, Tamworth which you would find interesting especially as there are a few members with S Types there.
Lancaster Jaguar are in Ventura Park, Tamworth, very close to the A5. I live in Mere Green, Sutton Coldfield so it sonly 8 miles away.
Regards,
Peter.