Hello and welcome to the forum.
Common faults include...
Window regulator failures.
Rear axle bushes de-bonding
If the car has 17'' Silverstone wheels you must check them thoroughly as they do have a habit of bending.
Tyre pressure monitoring system (if fitted) faults.
On your car make sure the cambelt has been changed,it is due at 72k OR 5 years,the last bit is the part that often gets over looked although a main dealer should be aware of this (some are more reliable than others).
It's already had a new
,try and find out the circumstances behind the failure.If the engine started to run on it's own
then engine failure could be just around the corner.
Make sure you get a spare keycard with it,if the cards give problems then it doesn't neccessarily mean an expensive repair as there is a company that can repair them,but if you only have one it will mean that the car will be out of action for a few days whilst the card is sent away.
The Laguna 2 can be a troublesome beast,but at least now all the common failures are well known and there are now cheap fixes to many of the faults.Cards can be repaired (as said above) meaning that paying Renault £200 for a replacement and programming is usually replaced with having it repaired for £25,at one stage if a front lower suspension joint went it required a complete wishbone but now aftermarket joints are available for a fraction of the cost,window regulator repair kits are available for much less than the £150 Renault used to charge for a complete replacement etc,etc,etc.
There is a bucket load of info on the forum,a quick search should show up a number of threads on this subject,but as said in the posts above,not many people join the forum to sing about the virtues of their car,it's usually just to try and get an answer to a problem.