Ok.. Number 1 always says 6098
Number 2 just goes to number 3! Number 3 always says 31670, number 4 goes to 6, number 5 just lights up every digit on the display, must be a tester. Number 6 is that sort of stopwatch, number 7 revs! Number 8 should be a trip but doesn't seem to move! Well just written all that through my phone lol, now i'm gonna go try sort my crappy alarm!
Apologies for digging up this topic, but I can offer some info on this 'secret' mode;
Entries 1 and 3 seem to be fixed in any particular instrument cluster, but can vary for other engine/transmission combinations, e.g. the humble 1.6 'AEA' engine has #1 as 6679, while for the 2.0 8v (ADY & AGG) it's usually 6214
Entry 2 is mentioned as being a destination market indicator, with the u.k. apparently being 3
Entry 4 shows the number of engine cylinders, so a VR would be the exception in having the value 6 rather than 4
Entry 5 simply shows every segment of the displays, even unused Mfa arrows (if present) on some lower spec units
Entry 6 advances with rotation of the speedometer sender - I've seen it ticking away with the engine/transmission turning, but the driveshafts disconnected
Entry 7 is indeed an rpm indicator/digital tachometer, which I think is a handy check of the crank sensor for engines that have one, since it registers at cranking speed. The increment amount can vary, some are 50 rpm interval, some 100
Entry 8 I'd guess is the software edition embedded in the unit - it's also shown as 'SW #.#' on some units' part number label
The fuel gauge fluctuates while driving with the mode active since it by-passes built-in damping
