According to the Guide, there seems to be a big difference between the Xsara and the Xsara Picasso.
Of the Xsara, it says "give it a wide berth".
Of the Picasso, the 2005 Guide says it "scores well for interior space and versatility, but it's no driver's car. The diesel versions have impressive fuel economy but also some reliability problems". They seem to be related to the 03-05 diesel models, which get a black mark for 'niggles' as they're otherwise average across the board.
The 2006 Guide says (of the Picasso), "It's comfy and practical but make sure you haggle hard to help offset high depreciation. Check the fuel system if buying a used diesel." Only 54% would recommend it to a friend and the diesel model comes out as average across the board except for faults, for which it's rated only one star.
It lists the diesel fuel system, dashboard switches and central locking as troublespots in the 2001-03 models and central locking in the 2004-06 range.
They don't seem to rate the Omega, Pro: "not pleasant to drive, it suffers from poor reliability and it depreciates quickly."
Of the Bentley Continental GT Coupé, it says: "strictly for the phallically challenged with money to burn."