Their problem is that this particular car is type approved on 215/50 R18s and even though the alternative wheel and tyre size is 215/60 R16 they can't legally change that prior to the sale. However, as long as the circumference of the tyre is the same, switching to the smaller rims and deeper profile tyres won't affect the AWD system, the steering angle sensor or anything else. Tell them your order depends on the car having all season tyres and if they cannot supply it on all season tyres you will go and buy a Vitara or something else instead. Worth checking the Michelin, Goodyear, Vredestein, Bridgestone and Nokian websites to find out if that size tyre is available as al all season. Or contact www.mytyres.co.uk or www.tyrement.co.uk