So after all that - did we ever find out what the ideal donor 20VT car would be? Sticking with transversely mounted engines in front wheel drive cars keeps things in a nice orderly fashion we have options like the Golf, A3, Bora, Leon, TT, Octavia. The BAM engine seems to have a good power output, transverse mounting and it is used in more common cars. There is a nice Salvage Seat Leon 20VT on ebay which has the BAM engine. Only £1650. Buy it - nick the engine, bits and box then flog the rest. I reckon you'd probably get your money back on it. This Link is useful for determining what engines exist, their power output and their mounting type. Does a the BAM 20vt engine actually fit the gearbox bellhousing on the Lupo or will you have to fit the gearbox from the donor car aswell? Which then poses the question of mounting positions as no doubt they will be different. Driveshaft length also comes into play unless it's the same - which would be too easy so that won't be the same either.