Is there any way to stop you being a crook? 'cos that's exactly what you
are if that's the game you're playing.

Thankfully, the odometer in the 924/944 family of cars is quite resistant
to this: When I was looking at used 924 cars years back, it was
surprising how many had a broken odometer (either frozen or with the
digits all out of alignment).

What did annoy me was when my 944 developed a genuine fault, and the
speedo unit went off to get the offending cog replaced - the fault had
meant that the car was "putting on" an extra 100 or 1000 miles every so
often (sometimes an extra 100 every mile!) as a consequence, my odometer
now reads about 20,000 miles more than it should - the company that
repaired the faulty unit refused to set the mileage back 20,000 (or
couldn't, never quite sure which).

As much as I despise the insurance companies and their less-than-honest
business practices, people who even think of doing what you're trying to
do sicken me. It's not just the fact that a lot of us out there are
paying premiums that are fairly high because we're honest, but one of us
might one day want to buy your car, and find ourselves with a lemon that
has a higher mileage than we were led to believe. I just hope that, if
you do suceed, that you are caught.

let's leave ethics aside for a moment.  I restore old cars - by that I mean
50 to 70 years old - I have on occasion set the odometer to any number that
tickled my fancy - who knows how many times it had been around or if it was
accurate - now, if I claimed that it was "original miles", that would be
fraud, but I don't, I keep the cars.

that said - on a 944, the "common" odometer failure is a soft gear that just
crumbles - you can buy replacements on the web.  If you remove the speedo
cluster and open it up, its very simple to set the odometer to anything you
please, just take it apart and set it to what you want - agian, it's fraud
if you attempt to sell the car based on non-original miles.  I've taken
several apart to replace the gear, and it takes a couple of hours if you
know what you are doing.

if you take some action to deceive your insurance company, there is a good
chance that if a situation arose where you needed insurance, they could
discover this fact and deny liability, with potentially unpleasant
consequences.