No thanks...had my engine replaced, now my car is again at the dealers because of fourth misfire.
Having just bought one late last year (March 2012 registered) and run into the misfire within 5 months, now have had a new (CTHE) engine put in – yes, I probably would.
Don’t think the CTHE went into the Cupras until just before the facelift (late 2012?), check the build sticker on the polystyrene spare wheel surround under the boot floor. Battery in boot isn’t a guide either, these (inc ours) still had CAVE engines. Don’t know how to spot CTHE engine if you suspect it’s been changed, not sure any external differences.
I’d look for the condition of the exhaust and surround, really sooty means high oil and / or fuel consumption. I’d check the fuel consumption if I could (run it until warm then zero the MPG guide pressing small button under right stalk, use end buttons to cycle through display). Drive ‘normally’ without using the loud pedal, you should get 35+ mpg, if it;s under 30mpg walk away.
And get as much warranty (covering all aspects of the engine) as you can.
It’s a great little car, brings a smile to the face in direct proportion to how far the right pedal is pressed down!