Head gasket had gone when I bought the car, unfortunately I didn't know about it, so after I had it repaired at a cost of £500, I wrote to the previous owner telling him of the cost, he sent me a cheque for £200 towards the cost.
Bad earth on the rear lights caused intermittent warning lights to come on, easily fixed.
Starter motor solenoid doesnt always work first time, has been like this since I bought the car, but always starts after a couple of turns of the key.
Front pads wear out at an alarming rate due to sticking calipers, so have had new ones fitted at a cost of £130. Plus new discs at £25 each.
New exhaust, cost £200.
New comfort spheres fitted at £30 each corner, nothing wrong with the old ones, but found the ride a bit hard, I now put the suspension into sports mode for a stiffer ride if needed.
Car takes a while to rise after being left for a couple of days, so maybe a new hydraulic pump is needed, about £40.
Car has never let me down, and after 40000 miles in 2 years I`m still loving it.
Driven carefully I have achieved over 50 miles to the gallon, just under 40 is the average.
Gearbox is real crap especially when cold, apparently normal but I have driven other XMs which were much better. Autos are nicer, but cost a fortune to repair, and apparently they all need repairing sooner rather than later.
My next car will be another XM, nobody likes them so they are dirt cheap second hand bargains.