Hmm, whether they're going to change the test to look for diesel particulates? - assuming they don't do it now?
I only say this as my son got caught out recently as he bought a 1.9td W reg VW T4 van and has fallen foul of the London Emissions Zone and has now got 3 x £250 fines in as many days! No warnings!
His options are to either :-
Convert to petrol (which he is going to do with a 2L 16v from a MkIII) or :-
Fit a DPF (£3500 plus vat) and have it tested every year by VOSA which is apart from the MOT at the moment, so this 'other' test for particulates is perhaps going to be bought under the wings of the MOT?

Or (of course) he could sell it on.... but he's fallen in lurve with it
