The loud metallic clunking noise as you hit the gas should be easy to find. There has to be obvious slack in the drive chain (half axles, propshaft, differential, dry clutch) or lots of play in the gearbox.
The vehicle is on axle stands nowand checking for free play with each side tried. No luck yet, so gearbox cover and the belt drive variomatic clutch cover removed, after a struggle with the long plastic air tubesThe belt drive cones looked clean and healthy. tried the belt tension but this shouldn’t be a problem with any slack taken up as the cones take this up on spinning the primary v secondary V cones.
Will I get the gearbox back together is the next question!!!