Rear Side Windows Kit for Porsche 993: Essential Parts and Installation Guide

If you own a Porsche 993 and need to replace or upgrade the rear side windows, a dedicated kit can simplify the process and ensure a proper fit. These small but important panels—often called quarter windows or pop-out windows—are available in both glass and polycarbonate, each with its own benefits. This guide covers what to look for in a rear side windows kit, the materials used, installation considerations, and how to select the right parts for your 993.

Why Replace the Rear Side Windows?

The rear side windows on the Porsche 993 serve both aesthetic and functional roles. Over time, original glass can develop scratches, delamination, or seal failures. In track or performance builds, owners often swap glass for lightweight polycarbonate to reduce weight and improve safety. Whether you’re restoring a street car or building a weekend racer, a quality kit ensures these windows fit correctly and seal properly.

Glass vs. Polycarbonate: What’s Best for Your 993?

OEM-Style Glass Kits

For a factory restoration or street-driven 993, tempered glass kits offer the best optical clarity, scratch resistance, and long-term durability. These kits typically include the glass pane, new rubber seals, and sometimes the pop-out mechanism hardware. The glass matches the original look and sound insulation. However, glass is heavier and more prone to shattering under impact.

Polycarbonate (Lexan) Kits

For track use or weight reduction, polycarbonate windows cut weight by up to 50% compared to glass. They are more impact-resistant and can be tinted or clear. Most polycarbonate kits include the window, mounting hardware, and instructions for permanent installation (often bonded or riveted). Look for kits with a scratch-resistant hard coat to extend clarity. The trade-off is less scratch resistance and potential for clouding over time. Polycarbonate also transmits more road noise.

Key Components of a Rear Side Windows Kit

A complete kit should include:

• Left and right window panels (glass or polycarbonate)
• Rubber or foam seals for the perimeter
• Retaining clips, screws, or rivets
• Pop-out latch assembly (if retaining the factory pop-out function)
• Installation instructions specific to the 993

Some kits omit the pop-out hardware if you plan to bond the window permanently. Decide upfront whether you want the window to be removable or fixed.

Pop-Out vs. Fixed Installation

The Porsche 993 rear side windows are designed to pop out for ventilation. If you want to keep this function, choose a kit that includes the latch mechanism and hinge pins. Fixed installations (bonded common in track cars) are simpler, lighter, and more secure but eliminate the ventilation option.

What to Look for in a Quality Kit

• Fitment: The kit must be specifically for the 993 (model years 1994–1998). Generic kits require modification. Confirm part numbers if possible.
• Material Thickness: Polycarbonate should be at least 3/16 inch thick (4.8 mm) for rigidity.
• UV Protection: For polycarbonate, a UV-resistant coating prevents yellowing.
• Seals: High-quality EPDM rubber seals outperform foam for longevity.
• Hardware: Stainless steel or zinc-plated hardware resists corrosion.

Installation Overview

Installing a rear side windows kit is a DIY-friendly job for someone with basic mechanical skills. Steps include:

1. Remove the interior quarter panel trim.
2. Unbolt or pry off the old window (may require cutting adhesive).
3. Clean the window frame thoroughly.
4. Test fit the new window; trim seals if needed.
5. Apply sealant or butyl tape per kit instructions.
6. Install and adjust the pop-out latch (if applicable).
7. Reattach trim.

If bonding polycarbonate, use a dedicated adhesive like SikaFlex or 3M Window-Weld. Allow full cure time before driving.

Common Mistakes to Avoid

• Overtightening fasteners – Can crack polycarbonate or distort the frame.
• Skipping sealant – Leads to wind noise and water leaks.
• Using wrong adhesive – Some adhesives react with polycarbonate and cause crazing.
• Ignoring pop-out alignment – Misaligned latches cause rattles or difficult operation.

Maintenance Tips

• Wash polycarbonate with a soft cloth and mild soap; avoid ammonia-based cleaners.
• Apply a UV protectant spray periodically to prevent clouding.
• Check seals annually for wear; replace if they harden.
• For glass, simply clean with standard window cleaner.

Where to Find Kits

Specialty Porsche parts suppliers and motorsport vendors offer rear side window kits. Look for brands that specialize in 911 parts, such as Pelican Parts, Design 911, or FVD. Always verify fitment by calling or checking the product description. Some track-oriented companies like Rennline or BBI Autosport carry polycarbonate kits specifically designed for racing.

Final Recommendation

For most street-driven 993s, an OEM-style glass kit with new seals is the best choice—it maintains the car’s character and resists scratches. If you track your car or want to save weight, invest in a quality polycarbonate kit from a reputable supplier; make sure it includes a scratch-resistant coating and all necessary hardware. Whichever you choose, follow installation instructions carefully, and don’t compromise on seal quality. Your 993 will look right, stay dry, and perform as intended.