Spectra Premium M400R Lower Rear Quarter Panel Patch Passenger Side

The Spectra Premium M400R is a replacement lower rear quarter panel patch engineered for the passenger side (right) of classic Ford Mustangs. Designed to address one of the most rust-prone areas on these iconic vehicles, this panel delivers a precise, OE-style fit that restores structural integrity and the original body lines of the car.

Stamped from high-gauge steel, the M400R is built to match the contours and dimensions of the original equipment panel it replaces. Whether you're performing a full restoration or targeted rust repair, this panel provides a clean, workable surface that takes well to standard fabrication and finishing techniques.

Key Features:

• Replaces the lower rear quarter panel on the passenger (right) side
• Stamped from high-gauge steel for strength and durability
• OE-style fit, form, and function for accurate panel alignment
• Dimensions: approximately 17.5 in. H x 27 in. L
• Natural (unfinished) steel finish — ready for prep, primer, and paint
• Sold individually (single panel)
• Cross-reference: Keystone Auto Industries GMK302369071R

Spectra Premium has been a trusted name in replacement body panels and automotive components since 1989. The M400R meets or exceeds the performance standards of the original equipment panel, making it the dependable choice for restorers and collision repair professionals working on classic Mustangs.