I've heard the ford units suck. Dmf and injector problems are expensive. For 3k what about an Ibiza pd130. Decat and your running 160ish bhp and a crap load of torque. Or a Octavia, bora, Leon, golf, passat, a4 1.9tdi?
A few odd ones but if it's motorway miles I'd stil perfer a German diesel.
Clio 172 average 36mpg, quick, lots of equipment.
330d e46 will be higher miles but still nice cars.
Mx5. Small fun?
Lexus gs300?