I'm looking to buy a car that is some distance away. It has just passed MOT with no advisories. The owner has sent the following pictures of the sills and underside. How do these look the your experienced eye? Is it worth considering given the surface corrosion on the sub frame? What could be done to prevent further decay?

Hi Michael, welcome to the forum, sills look good, underside looks scabby but representative. I had mine cleaned off and sealed, to neaten it up and offer some protection. A filthy job a didn't fancy myself so paid ~£200 for. Well worth it in my book, peace of mind etc 😉

Thank you for giving this some perspective. I had a classic car inspector look at these pictures and he thought I should walk. I think he maybe used to looking at rather more coveted classic cars. I understand that the sub frames can rot through and replacing them is an expensive job so I suppose his advice was based on this potential liability ... 

If you can get it cheap as a restoration project, go for it. Otherwise, you may be better off finding something better. As those who claim to know about these things will tell you, what you see is only a third of the rust. The sills are under attack and I think you will find that the wheel arches are too. Remember that rust can start from the inside and work its way out, so when you see it on the outside, the damage may already be substantial.

3 hours ago, Suppedraken said:

If you can get it cheap as a restoration project, go for it. Otherwise, you may be better off finding something better. As those who claim to know about these things will tell you, what you see is only a third of the rust. The sills are under attack and I think you will find that the wheel arches are too. Remember that rust can start from the inside and work its way out, so when you see it on the outside, the damage may already be substantial.

Well, it's in the mid (£4K) price range for S Types and the vendor has done quite a lot of work on the car so I don't think they'll move on the price. I've had other cars with similar issues, wire brushed the subframe and painted with red lead. That worked because - as you say - the rust was building from the outside in ... it's difficult to asses that from pictures.