Delrin is a bit of a specialized bushing material - On cars, you can really only use it in joints which rotate on one axis. Delrin is an extremely rigid material. It's so hard it's literally on a different hardness scale from rubber or poly. Yet its threshold of plastic deformation is so low that if you manage to bend or dent it in any measurable way, it won't spring back - it'll just stay dented. Delrin is also unique in this crowd as it's self-lubricating. This means you don't have to keep regreasing them as you would a poly bushing, nor do you have to replace them as often as any of the other bushing materials here.

These characteristics make the stuff great for pivots that only need to rotate on one axis. Good places to use Delrin would be in control arm pivots on a double A-arm car (e.g. Miatas) and the shifter pivot bushings on cars with cable shifters. Just make sure that the joint really does operate on one axis before you install them. Don't, for example, put any Delrin at the front end of any double A-arm Honda. All of the joints in those setups operate on at least two axes (many of which are designed for high misalignment), and it will gouge the hell out of your nice new bushings.

Although you don't need to do it often, regular maintenance is crucial with Delrin bushings. Delrin joints need to be periodically disassembled and cleaned (once a year or so). The reason is that moisture tends to get trapped between the Delrin and the metal sleeves and you get surface rust between the two. This causes the metal to stick to the bushing, which, if left alone, will cause the joint to seize. Sanding all of the surface rust and lightly coating the bushings with marine grease helps fend this off, but this is something you do need to stay on top of.

Between the maintenance and the NVH (which will be transmitted right through the bushing), you probably won't want to install Delrin suspension bushings on your street car. On a track car / race car though, it's a great material that、if used in the right places, works better than polyurethane and save you a ton of money over spherical joints.