The six people would not have damaged it unless there was already something on the way out as they are built to carry 5 passengers and luggage. You need to check the suspension as something that was worn may have failed.

You also realise it is illegal to carry more passengers than there are seatbelts?

Broken rear spring(s)

possibly broken spring.

Well as it was over loaded then it could be just about anything. as you have put more weight in it than you should have done. so it could be expensive to repair now.

So basically I was driving 6 people in a 5 seater Clio 2001 1.2, only drove about 2 miles. Now when I slow down and to about 5 miles an hour and slightly turn the steering wheel I hear a small sort of grinding noise, only happens every now and again, I wasn't sure what it is, now when I push down hard on the back of the car I hear some clinking noises, could this be my cars suspension is nadkered because I had 6 people in it? And if so how much roughly to get it fixed, thanks In advance