If you can I would wait another year or so until the later Laguna II Phase 2 models become more affordable on the 2nd hand market..
Post 2005 facelifted Laguna's have many modifications which improve upon the early niggles.
Having said that though I have run my 2001 for approx 60k miles without any big problems - maybe I am lucky - maybe I drive carefully enough not to strain the car into an early grave - maybe I ensure the car is well cared for and maintained - lots of maybe's - mines only a frugal 1.8 16v but there's a few V6 owners here who will maybe comment on the autobox for you though..
Have added v6 to the thread title in case anyones searching around..
Also moved post into the Laguna buyers guide section.. Take a look at this section for further posts about buying a Laguna and what to look out for..