Things I could imagine in the lower left corner (maybe on some metal holder in some chassis where needed):
Nice, but prob’ly overpowered:
A (maybe very slightly zoomable) cubic outside view of your mech from an elevated behind position (fixed camera), one that would include laser beams and projectiles in realtime as they impact on you. Its purpose would be so that you could easier see from what angle a laser is fired at your back compared to radar. It could be given a holographic semi-transparent look also.
MLP franchise (licensing can be worked out, just split profits of MLP-related sales and convince them this actually helps their franchise, too). This would additionally yield you mad positive mentions and publicity in the magazines. Speaking of, NOW is the time to make sure you get media attention. Get ads into major pc magazines and arrange for previews if you haven’t. It’s more attractive to people to be part of a pioneer crowd than to join already grown structures.
Back to topic:
MLP example:
A small animated Applejack figurine looking ahead, going “Yeehaw!” when you click it (get samples of the original voice actors, this stuff matters), and occasionally bucking out when you fire something heavy.
Fluttershy could do her “Woohoo” when you score a kill, stuff like that.
Other:
A greyish-black rubber duck like the one from that old Convoi movie, preferrably slightly animated (make it clench its fists under fire), and making angry duck noises conditionally / when clicked.
A rolled-up rattlesnake. It could turn its head to the nearest enemy (if visible/on radar) and conditionally rattle.
As you can see I’m into functional things and pet-likes. For when it gets lonely in the cockpit!