Hi, John. Just incredibly useful. Really appreciate your time.
Boy! that's a big old boot space. Anyway, the CTEK unit comes with a set of eyelets (M6) about 35cms long. Not quite enough to get the connection above the battery compartment foam cover. So I got the eyelet (M8) accessory from CTEK, with the traffic light indicator, which is 500cms long.
As advised not to attach to negative battery post, needed a negative chassis bolt quite near to the positive battery post, as not much separation between the CTEK eyelets. Finally chose as shown upper right of battery.
Then, took your advice and got the long extension from CTEK, which is 2.5M long. This easily extrudes from under the foam for easy connection to the unit, whilst still not able to see the traffic lights on the connection.
Wanted to get a water proof extension from mains plug (in garage) to car boot outside so with a 106cm long fixed car-side lead on the unit, just about makes it so long as I waterproof the connection which necessarily has to be outside. Noted CTEK say lead from unit to car should not exceed 3M.
I did try putting an extension lead into the boot but the lid does not close due to safety override.
Hope useful to others. Thanks again. Barry.