Private plate swaps can be notoiously slow to update themselves,so it could be a completely legitimate car.Having said that,there are plenty of other Lag 1's for sale out there,so if your not completely happy with it,walk away.
Lag 1 phase 2's are,on the whole,very good cars,just make sure when the cambelt was last changed as they can be expensive to replace properly,and even more expensive to fix if they snap.
Gearboxes are a known weak point,but it's mainly the dTi diesels that have problems.Just make sure that the gear change is smooth and that there are no nasty noises from the box in any gear.
The 1.8 16 valve engine also suffers from regular
failures,but these are getting cheaper to replace and are an easy DIY job.
Thats it off the top of my head,but as I said,if this car doesn't check out 100%,then walk away.