buying a new steering wheel for my s-max of a dealer on ebay, how do i find out if the wheel fits my s-max?? he has the part number but i cant find mine??

You have to look at the back of the current wheel. There are two designs - the early ones (2006-2007.5) have 3 mounting points for the airbag, the later one's have 2 mounting points - from the front they look physically identical, so it's only by checking the mounting points from the rear of the wheel that you can be sure you get the right one.

You can do this without removing the wheel - just remove the cowling round the steering column then check how many spring clips there are. The earlier wheel has 2 at the top (one top right at 2 o'clock, the other top left at 10 o'clock) and one at the bottom (dead centre at 6 o'clock). The later wheel has one at each side (3 o'clock & 9 o'clock).

Also the cruise control buttons (if fitted) are not compatible, but they can easily be swapped from one wheel to the other.

Both wheels will physcially fit all years of smax, but the airbags are not interchangable due to them having different mounting points, so if you get the wrong wheel you will have to replace the airbag also.