More antic-data: i worked with a guy whose brand new RX-8 needed two engines in the time we worked together. Granted, his was a 04 automatic, which is the worst combo. But still, Mazda didn't go out of their way to extend the engine warranties on the early RX-8s for no reason.
Did you happen to have an 08+ model with the updated engine and/or remove teh catalytic converter?
My RX-8 needed a new engine at 50k miles. As you likely know, if you start and stop an RX-8 engine without allowing it to warmup you risk flooding the engine.
In my case, I was taking a trip with my family and my RX-8 was blocking the driveway. We were running late for the flight, so I pulled it out, parked it back in the driveway, and let it idle there for 30 seconds knowing I'm not supposed to shut it down so quickly. But I had people waiting for me and what am I supposed to do, say "Sorry I own a strange car and I need to drive around the block for a bit to let it warm up!".
Of course that flooded the engine, but I didn't know until I got back from the trip. I followed all the instructions to de-flood the engine but it wasn't working for me so I had it towed to Mazda where they probably screwed it up further. It was there 2 weeks before they told me the engine needed to be replaced. They eventually had to fly an engineer from Japan to replace the engine since the dealer apparently had no one capable of dealing with rotaries. I think my car was at the dealer for a good 2 months. Thankfully all covered by warranty.
Long since mattering, but you could move them like this if you started it, rev'd it beyond 4k RPM, and then shut the motor off prior to it dropping below 4k. Basically, the idea was the rotors would force the fuel / oil mixture out of the crankcase and keep the spark plugs from fouling.
I loved my RX-8, but it was a pain in the rear. Switched to a WRX and got 50% better gas mileage, more power, more torque, and way more room. This of course bypassed the need to check / refill the oil every other fill up (aka, every 300-ish miles) all while trying desperately not to burn your hand.
I also experienced this flooding issue. Running it to a high rpm before shutoff to avoid the flooding, was a convenient workaround.
Why flooding the car (or frankly doing anything to my RX-8's engine) would require it to be replaced seems ridiculous. The casing of the engine is a solid piece of steel. Removing the ring gears and shaft (which you have to do for cleaning every 100k mi anyway), there's nothing to break.
Ofc, if you introduce the engine to some exotic combustion or get some foreign material in there, you could scar any part of the casing and that would brick the engine.
Did you happen to have an 08+ model with the updated engine and/or remove teh catalytic converter?