It would be nice to know if anyone has had success with the aftermarket DPF's ...the ones on Ebay in the £200-300 range.Had a very similar problem with my 55 plate 1.9 16 valve last summer. Had dpf cleaned professionally but limped home again after 300 miles. Turned out to be previous owner had a non genuine SAAB dpf fitted that simply did not have the capacity to run between regens without triggering the dreaded blocked dpf fault code and resulting limp home. Fitted a good second hand genuine SAAB dpf, forced regen with tech2 and problem was solved. 6000 miles later and it regens regularly on it's own. As an old SAAB technician once said to me, "you can't have champagne motoring at beer prices".
I havent heard any success stories as yet and believe it is because they are not manufactured with the correct ceramics inside.