Just nipped in the garage and there’s a small pool of fluid and a large damp patch on the floor. Car cover around the front splitter is wet, underside has yellow droplets.
Looks like something has decided to leak. Radiator was new 6yrs ago, car hasn’t ran for 5 months.
Behind grill/front row post is dry.
Has the rad died and why?
There are a couple of pipes you can check with the clam still on that connect to the solid sill pipes that run the length of the car, might be worth checking those - give the jubilees a tweak etc.
Only thing I can think to cause a failure whilst being laid up is not enough anti freeze in your coolant and maybe some freezing/thawing has gone on. Sounds unlikely though with modern antifreeze lasting forever, and as it’s garaged I guess it takes the edge off even the coldest night.
Has your header tank level gone down?
Car is garaged and the car is driven in, so front of the car at back of the garage, frost won’t be a problem.
I’ll check the header tank at the weekend and remove the access panels for a look. Are there any plumbing connections behind the front wheel arch liners?
If you remove the liner on the right hand side (UK driver side) you can just about see the inlet connection to the radiator but not great as it disappears into a hole. Removing the front undertray gives good access to both pipes as they connect to the sill pipes.
Yep the best view you’ll get is probably with the front undertray off, where the ARB is mounted you’ll see both inlet and outlet coolant hoses connecting to the chassis. I know of a couple of cars that have had persistent weeps here, so worth a check.
If you’ve lost a lot of coolant (sounds like a pretty significant amount?) then I’d be looking somewhere lower in the system, so those inlet/outlet to chassis connections are a good place to start. With arch liners out you can just about see the connections to the rad… but not very well!
Does this help ??
I think it’s is a 7mm hex on the hose clip, difficult to get a slotted screw diver on to it. Just nip it up it evidence of leaking
Cheers all. As always Exiges.com excell at being helpful 
I’ll have the car jacked up and access panels removed on Sunday to investigate.