Right perhaps time for a more measured and detailed description of the problem
while I used the term "serious" that is a relative term.... it's not a complete Niagra , empty the entire system in 1 minute jobbie....
here's how it presented....
over the last month or two, there's been a slow steady loss of coolant, but with no external symptoms to speak off, just losing a litre every 2 days or so...
then , the other day, I drove the 1.2 miles to the post office, and when I pulled up, there was a significant amount of steam escaping from the bonnet edges... on the front and near side and rear nearside
as far as i can tell, it only began to escape after the thermostat had opened and the whole system "comes online" as it were , after the engine reaches nominal operating temperature.
The Steam is obviously from somewhere low down , on the right (viewed from the front) near side of the engine... even I worked that much out..... and, seems to be right back up against the bulkhead from what the lads at the Garage told me...
their assertion was that even with the cowling off, and the system pressurised, they couldn't immediately or directly see where it was coming from.... fair play, they haven't charged me a bean for looking.... so wrong or not, at least they're playing fair and honest.... and My initial cursory inspection was curtailed as I couldn't see though the clouds of steam either... I'm guessing they pressurised it by running the engine, and weren't expecting quite so much steam....
They're quite happy to do further disassembly next week , and fix the thing for sure... but they're aware of my situation.. so they figured it would be in my best interests to let me have the thing back with their findings so far, and if I can sort it over the weekend... they're happy about that.....
Trying be fair, the Gaffer there is away on Holiday, and the builders start tomorrow at 8am building the new MOT bay.... so I guess they're trying to clear the decks while short handed, and figured I'd not be too upset to get it back un-fixed , I think they assume that because I live over the road, and they know we're a bit short on cash (that is also relative term.... we have income , but our outgoings right now are about the same as our income... leaving bugger all for emergencies or luxuries, or indeed, much else... )
, that they'd be doing me a favour.... they've always treated me fairly and well in the past... although not always as quickly as i'd like

so I'm prepared to give them the benefit of the doubt.....
Back to symptoms and the car...
There's NO ingress of steam or water in to the interior as far as I can tell.... hopefully ruling out the heater matrix and associated pipework...
I've consulted the Haynes book of Lies, and found it to be in chocolate fireguard territory... again..... no images or diagram showing what pipes go to and from anywhere....
and I can't see what's under the top layer of pipework either....
Xray specs would be handy about now....