The Volkswagen Golf GTI is a favorite among the Autoblog staff . Until recently, one among us owned a fifth-generation model. The current Mk7 is a great car, but it's getting along in years. It's been on sale for four years in the US and six years in Europe. Naturally, then, development on the eighth-generation model is underway, and spy photographers caught an early test mule having a bit of trouble on the road.This trouble did give us a good look under the hood, but the mess of wires and black plastic doesn't really reveal much. It's likely to have an updated version of the current GTI's 2.0-liter turbocharged inline four. We're hoping that Volkswagen will eventually bring us the 306-horsepower version from the European GTI Clubsport S Inside, we can see that the mule is a Mk7 model fitted with some updated equipment, most notably a new shifter, new HVAC controls and a new digital instrument cluster. Expect the new interior to better integrate controls for active safety equipment. Expect the full reveal sometime in 2019.