The undershields won't cover anything you want to see, especially at the rear end subframe suspension brake caliper mounts etc which is where Civics tend to rust, not forgetting the exhaust.

You don't need a garage to do this, the mk1 eyeball of someone with a bit of nous is enough, its in your own interest to do so, underneath is my first point of inspection and i've been back in my car on the way home within 2 minutes before now, having never so much as opened the doors or bonnet, the underside telling me enough.

If corrosion is getting to be an issue the MOT tester will often make an advisory note on the MOT, unless the car in question spent its first three years somewhere else this one appears to have been a Sussex car and given the low mileage unlikely to have seen much salt, but there's nothing quite like a poke nose for your own piece of mind.

Its the rear cross member and suspension frames that will show first, which you can clearly see from that diagram, and brake calipers can get alarmingly corroded whether steel or alloy, but you are also looking for any damage to or missing undercovers, and run your hands along the sills feeling for any problems or bent sills where the car has been dropped off a high kerb for example or jacked up badly by an incompetent, checking also the lowest part of the front skirt in case its been scraped on kerb edges or steep approach angle, and have feel how much muck and crud is rammed into the lip of the rear wheel arches...not sure if these have rear pastic inserts to prevent that not many cars do, if crud is packed in there it wants to come out if you buy the car and also gives you a clue it hasn't been washed underneath.

If you look at the MOT histories of cars that lived in Scotland you often find corrosion being mentioned on the very first MOT, in fact a Landcruiser i was perusing because it was too cheap for its year and mileage turned out to be a Scottish car for its first 5 years and corroded brake pipes appeared on teh first MOT @ 36k miles, luckily now with the addresses of mot testing stations on the .gov site its made checking where cars have lived their lives much easier so cars that have seen excess salt can be avoided...must admit i was abit concerned that a low mileage LC should be so cheap, but seeing the MOT history confirmed the usual rule, a cheap LC is cheap for a reason.

The problem being, there was a few years ago a big trade in buying cars at Scoittish auctions and transporting them to small time london car dealers for resale at higher prices to you wealthy middle class southerners..:-), these cars arn't going to fall apart but if left still caked in excess underbody salt they will succumb to problems much faster than a car that spent its life like the one you are hoping to buy would appear to have done, running round Gatport Airwick....as the late marvellous Ray Moore used to say.

Edited by gordonbennet on 15/10/2017 at 21:33

One car I looked at a few years ago, a not very old Civic, had the car jacked up at some point in the centre of the side sill which caused a flat spot in the sill, they tried to fill with filler and did a terrible job of it

The undercover was missing on it from the engine oil drain plug which according to my mate who had a type R causes more air drag on the underbody and less MPG because of drag

the under cover is designed to give better aerodynamics, so if a bit is missing- badly broken it may not give best fuel consumption, I was told up to 5mpg drop