Have been reading the forum quite a bit and have learned a lot from all the posts here.
I now finally have a question, which I hope some can answer.

In relation to fuse 22 and having the valves open, there is also the option to have a remote control to open and close (auto) the valves on demand.
However I have not seen any option instead to have a button or switch instead, is this not possible?

I was thinking two wired clips to the fuse 22 location running to the drivers side or centrol console and in between a fuse holder with the 20A fuse - which can be in the fuse box itself.
Wires used are 10 or 12 gauge with flexible pvc housing for temperatures up to 70c (or 200c would be better?).
This finally can be linked to perhaps a switch at the drivers side or perhaps one of the buttons like the heated widscreen, which I never use in a hot country.

Cost for all these will be a few bucks in comparison to a remote with wireless, is there any reason this has never been done?
Would the wire length affect the current to keep valves open? I don't see how this would be the case as the wires are not super long and should not cause current fluctiations too much.

 

Removing the fuse is what keeps the valves open, so the current is only flowing through the fuse when they close. No, that shouldn't be a problem. It's all about how much you want to rip apart your interior to run wires from the trunk to the driver seat (in the Vantage, it's fuse 22 in the rear fuse box, not the one in the engine bay; I think the DB9 is the same). Standard 20-gauge wiring should be fine, no heat protection needed.

 

I did exactly this on my previous Jag which has similar exhaust valves, mainly because it was de-catted so was a bit too loud to run like that all the time.

I found that after I trialed my Virage without the fuse it was still quite quiet in drive because the car seems so keen to change up as soon as possible if driven normally so I just left it like that. Sports mode or flappy paddle mode is a different matter

It literally takes seconds to pop the fuse back in if I want to exercise the valves but I can't see the need for that as everyone seems to run with them open anyway.

 

When i bought my 2006 DB9 it had exactly what you describe, a switch under the dash with two wires running all the way to the boot to replicate the effect of removing or reinstalling Fuse 22 at the flick of a switch and it worked fine.

However i have just changed this to a three way switch connected in the front footwell that allows normal (automatic operation, i.e. Fuse 22 in), loud (fuse 22 out) or in quiet mode all the time (by grounding to earth), easier than running wires to the boot and more choice!

 

Don't think I would need to rip apart the interior to do this mod, unless I wan't to repurpose one of the buttons (front screen heater), but then I would not be able to do a 3 position switch like what Phuket Paul did.

PhuketPaul - did it work with grounding even at higher speeds?
Though would this constrain the engine a bit, it can't "exhale" properly at the higher revs.

 

Get a simple wireless remote switch with a fob... locate it all right at the fuse panel cubby...I use a set up like that to switch my front and rear cameras...

Easy to install, easy to remove. Cost under $20.