Fuel-Cap Retaining Tether
Three-part retaining tether for the fuel cap, explicitly shown by the creator on an R171 and described as fitting many Mercedes fuel caps. The design comprises a cap ring, flexible cord, and eyelet. The source used ASA for the ring and hard Shore D56 TPU for the cord and eyelet, while noting that approximately Shore A95 TPU may also work. Install all three parts, verify the ring does not interfere with cap sealing or locking, keep the tether clear of the filler neck and hinge, and replace it if fuel exposure, heat, or repeated flexing causes cracks or loss of retention. No other generation is linked because the creator does not identify one and no exact child-component number was established.

Starter Cable Connector Housing
Two-piece replacement housing for the starter cable connector on a 2006 SLK 350. The creator modeled it after the original housing crumbled, printed it successfully in ABS, and warns that its position under the exhaust manifold exposes it to substantial heat. Use both housing halves, print only in a suitable high-temperature electrical-insulating material, inspect the cable and terminal for heat or corrosion damage before installation, maintain factory routing and insulation clearances, and discontinue use immediately if the print softens, cracks, or allows terminal movement. Fitment is source-backed only for the stated 2006 SLK 350 within R171.

Center-Console Magnetic Phone Mount
Three-file magnetic phone-mount body designed specifically to clip into the R171 center console without glue, drilling, or permanent vehicle modification. The source includes a one-piece model and a split base/top alternative; add a generic magnetic phone pad to the upper surface with adhesive. Creator photographs show the printed mount installed beside the selector in left-hand-drive vehicles. Use only the one-piece file or the two split files as a complete alternative, print in a cabin-temperature-capable material, confirm the mount cannot contact the selector or controls, route charging cables clear of moving controls, and remove it if it loosens or obstructs operation.

10.1-Inch Head-Unit Mounting Bracket Set
Six-piece bracket and spacer set for installing a Hikity 10.1-inch Android double-DIN head unit in a 2005 SLK 350 without drilling the vehicle. The creator replaced an Audio 20 unit, reports that installation was easy, and says the brackets will likely suit SLK 280 variants and the rest of the same R171 generation; no fitment outside R171 is claimed here. The large screen requires removal of the factory cupholders. Print in PETG, ABS, ASA, or another cabin-temperature-capable material rather than PLA, which the creator warns can soften in a hot car. Verify fastener engagement, wiring clearance, screen stability, and unobstructed access to the hazard and Airscarf control panel before driving.