Where can I find a custom radiator ducting, undertray, and front splitter combo for a Mazda RX-7 FD?

Based on the available technical details, a custom radiator ducting, undertray, and front splitter combo was developed specifically for the FD RX-7. Here are the sources and details on where to find them:

2D Performance / JKL Engineering Combo A complete set featuring custom radiator ducting and an undertray/front splitter combo was designed using lightweight composite materials, including Teklam (a fiberglass skin with a Nomex honeycomb core) and aluminum ¹².

• Availability: These parts were slated to be released through the website 2dperformance.com ¹². Later on, this custom ducting package and undertray were integrated into a group buy hosted by JKL Engineering, alongside a Mazdaspeed GTC replica front bumper ¹².
• Fitment Note: The initial prototypes and ducting were designed specifically around the Mazdaspeed GTC bumper shape, though contour modifications for C-West and OEM 99-spec noses were also evaluated to allow for broader fitment ¹².

Alternative: Custom 99-Spec Front Splitter If you are running a 99-spec front bumper and only need the splitter portion, another custom option was developed using marine board (with plans to duplicate them in fiberglass). This specific splitter mounts directly to the stock 99 front lip holes as well as the bottom of the stock oil cooler brackets for extra rigidity ¹.