So my Optima PC925 died on me once again (2nd one within 2 years), after searching I've decided to give a miata battery a shot. Wanted something more reliable for daily driving, so went back to lead-acid battery instead of AGM. I modified my old small battery (PC680) tray, welded an extra 90 degree aluminum plate to add space. Also extended the wiring for the positive terminal. Interstate MT-MX5 battery. Here's what it looks like with ETS Short Route UICP.

 

I think I'll do a Miata battery after my PC925 dies

 

Looks good, what years from the miata fit? Thanks Shawn

 

1998 model

 

If you don't have a small battery kit and want to be like me and buy a whole bolt in kit without modifying then English racing has a kit that bolts right in. This is perfect cause I didn't know how it would look in the car thanks for posting...after 2 days of forum searches lol.
http://www.shopenglishracing.com/Eng...ttery-Kit.html

 

Looks great. I am thinking about installing a Miata battery in the trunk so I get some weight savings as well as removing some weight from the front of the car.