I have owned a manual GB A160 for coming up 6 years and the only problems I've had is the MAFS sensor which these days is not an expensive item if you read my site , Drop links which are only £13 each and easily fitted and a stop light switch, 1 minute jon to change
I now do my own service and the car is very reliable, I wouldn't purchase a high mileage A class nor would I purchase diesel or automatic GB
I have nothing against diesels per say Just MB diesels.
Early A140 had a problem with timing chain adjusters jaming vary rare failure on other models but as with all cars the odd fault does arise, Good oil and change at the precribed time periods and there is no reason why you should have a problem.
For further details and purchasing a used A class see my site , go:-
http://www.aclassinfo.co.uk/index.html
Good luck take your time and do your home work,
