After becoming the first Jaguar XJ to be road-registered (on 1 August 1968), MWK 28G spent substantial time on the continent. Interviewed in Octane magazine in 2018, to mark the 50th anniversary of the XJ, Jonathan Heynes reflected -

‘I worked MWK 28G up into a press car, and it was probably the best of them. In June or July 1968, just a few weeks before the XJ6 was launched, I drove the still-camouflaged 28G out to Le Mans to meet the journalist Michael Sedgwick, who was borrowing it for a magazine feature. A weld on the exhaust downpipe fractured and we had to get it brazed-up locally – it wasn’t a big deal but typical of the problems we had to deal with on the hoof. We were such a small team, it’s amazing how well the car worked out! It really didn’t give a lot of trouble.’

It was also driven over by test driver, Jim Graham. Graham Finlayson, the renowned photojournalist, captured images of the car's journey through France and into Asturias, Northern Spain. As this was prior to the model launch, most photos show the car in various states of camouflage achieved with cardboard, paint and tape; Jim Graham is shown applying, tweaking and removing the camouflage in various photographs. The grille, lamp and rear wing profiles in particular were cleverly concealed.

The 2.8 litre cars developed an undesirable reputation for piston-holing, which was something of a surprise as the test drivers had encountered few problems.  Later the problem would be established as coking of the piston crowns, caused by the cars being driven gently on stop-start runs; whereas the test drivers had been driving long and hard. Jim Graham's remembers MWK as giving no problems, probably for this reason.

MWK 28G was used for climatic testing on long, hot runs around the region and some photos show the car's fluids being periodically checked for deterioration: an oil check on the Mulsanne straight for example, and a transmission fluid check at the bank of the Zamora reservoir.

The shots of rural Spanish life in 1968 are a time capsule: there are shepherds, farmers using horse-drawn carts, and an elderly lady selling melons by the roadside. One shot depicts a temporary timber bridge, re-erected each spring by the local farmers to give their flocks access to pasture.

MWK 28G returned to the region - a little further south, in Salamanca - in 2018 and its return sparked interest and memories of the original visit in 1968. Residents of Paradilla de Gordón point out that their road was so new it was both unmetalled and unnumbered at the time. The rough and potholed unmade tracks of the region had a reputation amongst manufacturers and motoring journalists as a proving ground for new models, and one especially iconic shot of MWK 28G shows it being put through its paces in just such an environment.

The journey down to Spain was an opportunity for the car to be tested for long periods, on tough roads and in a hot climate: but this was not the only purpose. On arrival in Leon, Jim Graham checked in to the local Parador - a luxury hotel, converted from what had been a grand 12th century monastery that provided lodgings for Camino de Santiago pilgrims en-route to the Santiago de Compostela in Galicia. There he carefully tucked the MWK 28G away, out of sight. For the launch of the model that would prove to be pivotal to the brand's future, Jaguar had arranged a Spanish photo-shoot with a supermodel and her photographer boyfriend. Jim Graham's rendez-vous at the Parador was to be with Veruschka and Franco Rubartelli: at the time, an internationally famous photographer/muse couple who had featured on the cover of every international edition of Vogue.