The short answer to your question is not very....
BUT,if you buy carefully and check the vehicles history(especially for a
replacement),then you should be OK.
The earlier Lag 2's were pretty troublesome,but as the model developed the faults got ironed out gradually.
The best advice I can give to you if you go for this car is change the
and filter every 6 or 9k,not the 18k recommended,and use 5w40 fully synthetic
.Also,find yourself a good independant garage or Renault specialist to carry out any work you can't do yourself.
Have a look around the forum as there is a mass of info on the Lag 2 on here,but remember that most people join here to get answers to questions regarding faults with their cars,so most of the comments are a little one sided.We don't get many people join up just to praise their Renault!.
Good luck and let us know what you decide.