Where is a good place to grind to level 99?

I believe I've found the best possible way to farm levels in this game. As mentioned in this thread, the giant golden bunny statue at the front of the Amusement Park is actually a level 80 enemy.

Pleasantly surprised to find out that big machine life-form statue with the horn and bunny ears in the amusement park is actually a living enemy. [...] It's a level 80 enemy and it's really only feasible to defeat it by hacking it. Which you want to do because each successful hack on it netted about 11,000 exp. 2 hacks + it dying got me like 50,000 exp (slightly amp'd by my Exp +5 plugin chip). Went from level 66 to level 70 from one easy foe.

You may have to attack it for a few minutes before it notices you and starts moving (you won't even see a health bar before then). Once it starts moving, the easiest way to kill it is by hacking it as 9S.

When I just tried this with an EXP Gain +6 chip equipped, I received 13,000+ EXP for the first hack and 14,000+ EXP for the second, then a ridiculous ~50,000 EXP for defeating it. I leveled from 69 to 74 in roughly 4 minutes.

Here's a video of the entire thing.

Side note: while waiting for the video to upload, I defeated it a second time and boosted to level 77.

Update: It took less than an hour total to boost from level 69 to 99 using this method.