You don't need light deflectors on a 2017 Sporty, we've had 2013; 2016 and 2019 Sporty's and never needed them.
You should also be OK for travel into major city centres, but be aware if there is any heavy fog/smog (not likely really this time of years, but when pollution levels are high CritAir can be be invoked).
As said, UK number plates stickers *easily available for about £1.50 the pair.
Breathalysers turned out to be a bit of a scam as the minister had shares in the company.
The Kia SatNav doesn't have speed camera warnings, but your mobile map/GPS may, so be aware. Also be aware that the French do access the DLA records to send you speeding fines

If you venture into Spain, for some weird reason they also require the UK oval stickers, like the old GB ones. So much for EU harmonisation!!
Also your breakdown kit (presume you'll have European breakdown cover) and you might want to think about the new V16 warning beacon, which transmits your GPS position on motorways. Otherwise use a flashing orange/yellow warning beacon, safer than trotting 100 yards down the road to warn traffic, then going back to collect in the dark, so have powerful torches, hi vis in the car for each passenger. We also take a tyre inflation pump, first aid kit and emergency foil blankets. Then if there's space left for your luggage, you're good to go!
