After many years with Skoda (and 4+ with Yeti), I'm thinking of changing this week for a Mazda CX-5. I have narrowed the choice to two cars locally (both from franchised dealers). Both are SE-L Nav spec.

I do around 15-17k p.a. One is a 2014 car with a 2.0 petrol engine with 18k miles on the clock at £15990, the other is a 2015 model 2.2 diesel auto with 34k miles at £16495. My wife thinks the 34k on the newer car (ex-rental) is too much. Which would you buy?