What car - Diesel motorway muncher, radar cruise, for 10k or

If you don't mind nearly new then a 3.0d is worth a look, not sure what your budget is.

BMW 330d
http://www.autotrader.co.uk/classified/advert/2016...

http://www.autotrader.co.uk/classified/advert/2016...

Mercedes C350cdi if you can find one or an E Class if you can't.
http://www.autotrader.co.uk/classified/advert/2016...

2015 Audi A4 3.0tdi Black Edition
http://www.autotrader.co.uk/classified/advert/2016...

http://www.autotrader.co.uk/classified/advert/2016...

2015 Jaguar XF 3.0 Premium Luxury
http://www.autotrader.co.uk/classified/advert/2016...