The other day I dropped my car off at a European specialist shop, and while I was there, a technician was working in the engine bay of a Mk7 Golf R, cleaning out carbon deposits off the intake valves.
Tough engine cleaning jobs used to be tackled with ground up walnut shells and apricot pits. Not unreasonably, a foaming agent that does the same job is particularly welcome. Wash this space: Etihad ...