I've shipped from Canada to Europe twice, once to France and once to England.
The French customs guy didn't even want to look at the bike or the registration when the bike arrived via air freight - his attitude was "would I bother looking at your paperwork if you crossed the border into France by road? No. So bon voyage, and get outta here, I'm having my coffee.".
Going to England, I shipped the bike in the garage of the Queen Elizabeth II (not exactly shabby transport), and when the bike and I arrived in the UK, the customs guy asked me a whole bunch of questions to make sure I did not plan to sell the bike, he checked my registration and insurance to be certain that both were valid for a long time towards the future, and I had to fill out a whole whack of papers. Then he cleared the bike into the country, and gave me a 20 page booklet that explained all the things I could not do (stay in the UK longer than 3 months, sell the bike, register the bike in the UK, etc.). I was quite amazed by all the trouble, especially considering that I only planned to stay in the UK for 3 hours - the time it would take me to ride from Southampton to the Calais ferry to France.
So, I suggest you have all your paperwork in order, and don't try any stunts, the Brits look at things very carefully.
FYI I am a Canadian citizen and my bike is registered in Canada. I didn't need (or get) a carnet.