Seat Back Attachment System

The OpenSourceEV Parts Seat Back Attachment System is a modular, multi-function mounting platform for the back of your Rivian R1S or R1T front seat headrest. Designed by Todd Stansell, manufactured and supported by OpenSourceEV, tested in Rivian vehicles, and built to handle real-world road trips. Expected to fit the upcoming Rivian R2 as well.

Unlike single-purpose mounts that only hold a tablet, this system lets you choose what rides behind your seat. Snap on a tablet holder for rear-seat movie time, a MagSafe phone mount to game, FaceTime or TikTok, a hook for dry cleaning or grocery bags, or a cup holder for drinks your second row passengers actually need. Swap between them in seconds with no tools required.

What Makes This Different

• Modular by Design: One base clip. Multiple slide-on attachments. Buy what you need now; add more later.
• Tool-Free Everything: The headrest clip snaps on, and every attachment slides on and off without disconnecting the base.
• 17mm Ball Mount: Industry-standard mount point. Available as a solo ball (bring your own holder if you already have one) or paired with the OpenSourceEV Tablet Holder (up to 11" screens) or the LISEN Offset MagSafe Holder. Optional 12" braided charging cable add-on in USB-C (60W) or MFi-certified Lightning.
• Cup Holder Option: Available in Regular and Large sizes. Regular fits standard cans, 20oz soda bottles, take-out cups, and 20oz-ish insulated bottles. Large accommodates 40oz water bottles and mugs.
• Hook Attachment: Sturdy enough for dry cleaning, bags, or a purse. Slides on in the same way as every other attachment.
• Open Source Design: Design files are publicly available under Creative Commons NC-SA 4.0 for personal use and remix.

Available Configurations

This is a single kit product. The base headrest clip is always included. You can choose to add any combination of:

• 17mm Ball Mount Only (bring your own holder -- reuse an existing 17mm-compatible tablet or phone holder you already own)
• Tablet Holder (with 17mm ball mount, fits screens up to 11")
• MagSafe Phone Holder (with 17mm ball mount, LISEN 17mm Offset, works with MagSafe/Qi2 cases and included ring)
• Hook Attachment
• Cup Holder (Regular or Large)
  

Typical configurations: Base + 17mm Ball Only (BYOH), Base + Tablet Holder, Base + MagSafe + Hook, Base + Cup Holder + Hook, or build your own combination.

Key Features

• Snaps onto the headrest hook on the back of either front seat. No tools, no bolts, no adhesives -- even during assembly.
• Compact, low-profile design sits flush against the headrest hook without contacting seat trim.
• Optional 12" braided charging cable add-on available in USB-C (60W) or MFi-certified Lightning. Validated to work with tablets and phones, clear everything, and have excellent strain relief and overall durability.
• Printed from ASA for superior UV resistance and temperature resilience up to 300 degrees F. Other options are made of inferior PETG.
• Designed by Todd Stansell. Manufactured, sold, and warranty-supported by OpenSourceEV Parts. 
• Fits all Rivian R1S and R1T model years (Gen 1 and Gen 2). Expected to fit the Rivian R2 as well.
• Made in the USA. 3D printed in Pittsburgh, PA. 

Installation

• Slide the headrest clip onto the hook on the back of the front seat until it snaps into place.
• Slide your chosen attachment onto the clip rail.
• Optionally insert the included locking pin
• Done. Remove by reversing the process. Stores easily in the rear door pocket.