So I’ve looked at a supercharged 4.2 and initially was quite happy with it but before putting my money where my mouth is we looked underneath and the rear subframe floods like it’s started to rust as pictured - would you leave it based on this?

Also it clearly has a gearbox leak is this common/ an easy fix or again is this reason to leave it? Sorry for low res pictures but don’t want to buy a wreck! Cheers

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Hi Dan,
I have a 4.2 supercharged, love it to bits, yes it has got some surface rust on the rear sub frame area.
I would suggest that all these cars , because of their underneath construction, create low air pressure voids especially around the rear with all the recesses. This results, (in winter), that salt laden spray gets sucked up into these recesses. This could explain why the rear brake pipe that runs across from left to the rear off-side wheel corrodes even though its in a "tucked away" area.
Would I walk away from buying ?, well no, its fixable if you dont mind getting dirty. There are plenty of good rust treatments available out there.
I did buy the car Ive got now complete with some rear underneath rust.
The oil leak, difficult one, depends where its from and how much, I cant really comment not having one (yet) sorry.

NB: All cars eventually recycle themselves unless its a De-Lorian, kept in a showroom or lives in a hot dry climate.

The rust doesn’t look too bad on the subframe , I plan to spray mine with Dinitrol when it’s warm and dry for a period of more than a few days
I’d be more concerned with wheel arch and tailgate rust ... there appears to be 2 types of L322 , those that rust in these places and those that don’t - get one that doesn’t show any signs of you can

The mechatronic sleeve on the back of the box can leak - but you should be planning an oil change on any L322 purchase so can address the leaking sleeve whilst the pan is off
However that looks to be leaking from the front? 4.2 SC - sold , now bought back
4.4 AdBlu Tractor - Stolen

that photo was pointing to the back so it looks like a rear leak. Is there much chance I will find one with no rust underneath? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

There is a chance you will find a l322 with no rust but it is slim to none in the uk. Mine is rust free but it’s a Spanish car, Australian and Californian cars are the same but ROW is prone to surface and occasionally more serious structural integrity compromising corrosion. Looking at your photos, I would say it’s topical and a weekend with a wire brush and rust treatment would sort.

Oil leak could just be the oil pan or possibly the output seal of the gearbox, 500 sterling should sort...factor in this cost into your offer.