It's ten years old so will probably be looking rusty underneath. Jack up and remove wheels, brush off muck from all the suspension bits. Clean, and then grease or paint the brake pipes and fuel line. Paint the springs with oil - I use old engine oil (much to the annoyance of one or two posters!). Paint anything you see that looks remotely rusty with oil - or even paint! Inspect the exhaust, wire brush the rusty-looking areas around the joints and give them a squirt of high temperature aluminium paint. I'm not sure if this helps as they corrode from inside as well, but our 17yr old Focus exhaust is original. Deal with any bodywork (e.g. sills, bottom of doors, around wheel arches) rust as soon as it appears.

Agree with lot of this except the old engine oil - can be acidic ( when stripping and old but rare engine that had been stored at an angle for many years - the part of the crank that had been submerged in oil was in a hell of a state) . However clean oil (I sometimes mix with Waxolyl) is your friend on metal suspension parts (not on rubber!) . I always grease brake pipes and have never had to replace one since I started doing this. I also like a squirt of 3-in-1 through the drain holes at the door bottoms, bootlid, bonnet and sills (easy to apply with spray can/plastic tube).

Keeping serviced is good but pay attention to brake fluid changes - I've drained some horrible stuff from cars over the years, when not in regular use any moisture will cause problems.

At least these days we have plastic fuel tanks - on old metal tanks when stored the latent heat of evaporation creates condensation due to a temperature differential

Edited by Big John on 02/07/2018 at 22:58

... Inspect the exhaust, wire brush the rusty-looking areas around the joints and give them a squirt of high temperature aluminium paint. I'm not sure if this helps as they corrode from inside as well, but our 17yr old Focus exhaust is original.

Talking of exhausts, their life depends on two things: whether your journeys are long enough to warm them through fully to limit internal condensation; and whether your car burns diesel. The exhaust on a diesel car is soon coated in soot, which protects quite well against rust. I have never had to replace the exhaust on a diesel car, and I have kept some for 8 to 10 years.