Honda have had their parts logistics based in Belgium for over 30 years.
In earlier days parts ordered by 8.00pm were delivered into dealers across Europe for 6.00am the next day using the TNT Express Worldwide Overnite European Air Network (as were urgent production parts sourced across Europe for factories for GM and Ford).
It worked very efficiently with excellent service levels well before the EU Single Market using pre clearance procedures for Customs.
I suspect these are now 2/3 day road movements through other carriers with no Customs pre clearance as the opportunities for further economies (with a noticeable, possibly thought acceptable, decline in service levels) were identified.