The Problem: UV Degradation

If you’re shopping for this part, you already know the story — after 25–30 years, the original regulator covers become brittle and crumble to powder. This is one of the most commonly reported failure points in 3000GT/Stealth owner communities.

Why This Happens:

The original part was manufactured using PC+AES (polycarbonate blend), which degrades under prolonged UV exposure. The sunroof regulator cover sits behind glass, exposed to focused sunlight day after day, year after year.

UV radiation breaks molecular bonds in the plastic through a process known as chain scission, progressively weakening the material until it fails completely.

This isn’t a design flaw or manufacturing defect — it’s basic materials science. PC+AES was never intended for 30+ years of continuous UV exposure. In the early 1990s, these vehicles were engineered for a realistic service life of 15–20 years.

Our Solution: ASA Material

We chose ASA (Acrylonitrile Styrene Acrylate) specifically to address this failure mode:

UV Resistance:

• Built-in UV stabilizers at the molecular level
• Acrylate component absorbs UV energy and dissipates it as heat instead of breaking bonds
• Used by automotive manufacturers for exterior trim that faces direct sunlight
• Maintains structural integrity indefinitely under UV exposure

Real-World Proof:

ASA is the material of choice for outdoor automotive applications—exterior mirror housings, body trim, license plate frames—precisely because it doesn't degrade under UV. If it can handle direct outdoor sun exposure for decades, it easily handles sun through your sunroof glass.

The Bottom Line:

The original part was engineered using 1990s materials science for a limited service life. This replacement uses modern UV-stable materials specifically chosen for long-term durability. Under normal conditions, it should outlast the vehicle itself.

Added Benefit:

Unlike the discontinued OEM part (MB968050), this replacement allows you to repair only what actually failed — without purchasing the entire regulator assembly.