User Craig has a
Saturn TDI which is also on the
TDI Forums.
Although the engine (and car perhaps, I am 4000 miles away and we don't get Saturns here) are different he may have a head start on the Petrol to Diesel conversion.
I assume as the L-Series sold poorly (according to Wiki-b@@dy-pedia) that examples will be available for not so much money ? Vectra B's can be had for 2-300 GBP here.