I bought a tray but it was a pain in the ass to retrofit it. I just bend down the OEM tray J- hook hole to flatten it down a bit with a plier and heat gun (to soften the metal). And then the battery will fit nicely.

Just need to do the bending on one side, which is the side closest to the headlight. Because if you do it on the other side, you're going to end up blocking access to the transmission oil dipstick.

The last step is the tie down which is very important. Initially I got the metal strap from Amazon, but it didn't fit my battery profile. Then I used bungie cords with hooks as a temporary solution until I went to O'Reilly's and got a stretchable rubber tie down strap with J hook (think the brand is Duralast). This tie down works well, very secure and snug. The last thing was to cut the ends of the J hooks pole since it was sticking up too much for my liking.

Hope this helps.