Hi
I've the same problem water under spare wheel with my XF Jaguar 2013 plate.
Only had this car nearly 3 years no problems then January 2020 took it to our local car dealer who said there's 6 inches of water in the boot, they had it for 2 weeks with nothing resolved.
Took it to Jaguar dealer and they didn't come up with a solution and we still have problem. I've been looking on other Jaguar forum sites and someone has suggested it could be a rear vent seal behind rear bumper below the rear lights (it's a known issue!!) Also said there's a grommet in the boot which can be removed and then drain water.
Our problem is still not fixed but having seen this solution from other people I may take it back to the garage and see if they can solve the problem by looking at the rear vent seal??
Hope this was of some use??
Julie
