I just bought a 2007 Mazda MX5, 42000 on the clock and in good nick. After having it a few days - I called the guy as its pulling to the left on acceleration. Also - Diff noise is audible too. He picked it up - took it to Mazda for a health check and the report says:
Front tyres are low
changed battering in key fob
slight corrosion to front discs
and I was spot on about the Diff
so when he's back from hols in 10 days time - he's gonna get the diff fixed and sorted.
to be honest - I'd be expecting him to put 2 new tyres on it at £100 a piece for Bridgestone tyres (recommended