Looks marginal, (as in, it looks to be on the borderline where perforation might be found in the worst bits) though its not possible to tell without probing under the paint.

I'd doubt its dangerous (as in significantly structurally compromised) and I'd doubt it'd fail an MOT (though IIRC, and I do, they can be pretty picky) but it might merit an advisory, and its likely to get worse quite quickly if remedial action is not taken.

It looks to me as if water might be getting behind the paint from the inside of the car. I'd lift the carpets and look for signs of leaks

If it were mine I'd grind the paint off, ideally pressure wash it to get rid of any salt, then treat it with aluminium (flattened cans in a power drill) and vegetable oil (linseed probably best) or an alkyd resin, flood coating the inside of the car so it can drain down through the weld seams, and spraying inside box sections. Not difficult but messy, and you probably wouldn't want to be doing it in the UK winter.

www.honestjohn.co.uk/forum/post/index.htm?t=110553...1

More conventional alternatives would be Waxoyl and underseal. Don't work as well but they dry quicker and won't grow mould.

It'd have to be quite cheap to buy it like that, though.

Edited by edlithgow on 21/01/2018 at 03:01

If you want the Honda for 1-2 years,I would spray it with Dinitrol 4941 - dries black. Hides all rust and slows it down. BUT it will come back again.. but more difficult for MOT inspector to see and com,ment.

If you want to keep teh car for longer, buy another.

And if you do buy it, get it cheaper. And check what advisories it had last MOT.

www.check-mot.service.gov.uk/

Thanks for the advice everyone I didn't buy it in the end, I did offer the dealer 1k off the asking price but unsuprisingly he declined.

I'm happy with that as I have no idea what else was under there. Out of intrest anyone know how much such repairs cost if done professionally

Intrestingly there was nothing on the MOT history no advisories which suprises me a little I guess its up to the MOT centers discretion what they mark as an advisory? I guess if you have a good relationship with them they just tell you verbally and don't blot the MOT history.

This is the second rusty FR-V I've seen, I guess its true that if the price is low there is usually a good reason.

Edited by howmuchistoomuch on 22/01/2018 at 23:41