What things should I look out for when buying a 2008 Ford S-Max?

I'm looking at buying a 2008 Ford S-Max 2.0 TDCi, 133,000 miles on the clock. It's priced at £2650 and I'm looking at it this week. What things should I be looking for which should have been changed already...

Are high mileage cars worth the risk?

Are high mileage cars with full history worth buying?

Is it wise to buy a diesel Mondeo with 140,000 miles on the clock?

Would you buy a Ford Mondeo diesel with 140,000 miles on the clock? The car is 15 years old.

What are the pitfalls of buying a high mileage A4?

I am interested in buying a Audi A4 2.0 TDi S-line, Multitronic with 153,000 on the clock. It has full Audi service history and has had them regularly, every 10,000 miles. The car looks immaculate inside...