Question About The 1.6 Starter Motors?

CAR: Ford Focus (Zetec)

2007 ('57 plate)

1.6 Petrol

I'm writing this to ask you all a question. He only bought it in February, his car was written off then we bought a LEMON then we bought this Ford. I noticed on the Forecourt that the starter motor didn't sound too healthy. However I also picked up on other faults and asked them to check them out before purchase. Since purchase the starter motor has been playing up on and off, it went back them for a check up, and nothing was picked up. Today he's taken it to an independent mechanic, who has cleaned up one connector on the starter motor and has advised it may not last another month.

My question is this, I've been told these Duratech engines are too 'exposed' to the elements and that causes damage to the major components, such as the starter motor but I feel that's a lie. Surely the starter motor is nothing to do with an 'exposed engine' - all starter motors are exposed as it were. I have my own car and I have always done my own maintenance to them, I've done it all from re-wiring air bag connections, ABS speed sensors, even done the rocker cover gaskets.
His car is a 2007 model if this helps anyone.

What are the most common faults with this car? What should we be looking out for? I did notice a leak up the front end, under the AC unit, I suspected a leak - but then changed my mind as it was all directly under the RAD too with no obvious marks or indentations or damage. Garage today said it's 'condensation'.

Thanks for reading - sorry it's a long post