Between the tank and the engine ....
The fuel filter is located underneath the car on the passenger (right) side. It is located just forward of the fuel tank and is covered by a protective plate.
Try this;http://www.miata.net/garage/FuelFilterChange/index.html
See the Related Links section below.
You can get a 1999 Mazda Miata fuel cap at any auto parts store.
on the firewall passenger side
The 1999 Mazda Miata is a returnless fuel system. It has a Fuel Pressure Regulator in the tank (above the fuel pump), and a snub at the end of the fuel rail.
in the tank
location of fuel filter mazda 121
The 2002 Mazda MX-5-Miata runs on regular unleaded.
The 2003 Mazda MX-5-Miata runs on regular unleaded.
The 2004 Mazda MX-5-Miata runs on regular unleaded.
The 2001 Mazda MX-5-Miata runs on regular unleaded.
The 2005 Mazda MX-5-Miata runs on regular unleaded.