New owner of a 2006 RX-8. I filled the tank and discovered a leak around the fuel pump ring. It's had the recall service, so I assume they messed it up.
I didn't feel like buying the special tool to remove the plastic ring nut and I have a 3d printer....

thingiverse

 

for those who can’t or don’t want to make their own

https://www.fattimotorworks.com/mazda-fuel-ring-tool/

note that the 2009+ Series 2 ring is a different pattern than the earlier Series 1 ring
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Yeah I am going to be printing this tonight! Always have spare steel and useless sockets laying around.

Thanks OP.