Lance Tunick, Esq.
Vehicle Services Consulting, Inc.
P. O. Box 1015
Golden, CO 80402-1015

Dear Mr. Tunick:

This responds to your request for an interpretation as to whether Item 4A Glazing, "Rigid Plastic for Use in Side Windows," specified in Standard No. 205, Glazing materials, is permitted in the rear window that is behind a retractable roll bar in a convertible passenger car. As explained below, the answer is no.

Your letter asks for confirmation that a motor vehicle depicted in three enclosed photographs is a convertible, and asks whether Item 4A Glazing may be used in the rear and side windows of the convertible "if they meet the criteria of S5.1.2.11(a)(2)." The photographs depict a two door vehicle with two seats, space behind the seats, and a raked windshield. One photograph depicts a vehicle with no side glazing or roof. A second photograph shows a closer view of the top half of the vehicle, with a roll bar and an apparently retractable rear window. The rear window curves around the vehicle so that part of it can be seen from the side. The third photograph shows the entire vehicle with the roll bar and the rear window in place.

In a telephone conversation with Dorothy Nakama of my staff, you explained that by "side windows," your letter did not mean the glazing that rolls up and retracts within the driver and passenger side doors, but refers to the part of the rear window that is visible from the side. You explained that the vehicle includes a retractable rear window, retractable roll bar, and has a removable center or roof piece that can be stored in the trunk. You explained that the glazing behind the roll bar at the rear of the vehicle is of one piece. You also stated to Ms. Nakama that the vehicle has four designated seating positions.

We would agree that the vehicle is a convertible. NHTSA interpretations have consistently defined "convertible" as a vehicle whose "A" pillar or windshield peripheral support is not joined with the "B" pillar (or rear roof support rearward of the "B" pillar position) by a fixed, rigid structural member. The vehicle you ask about meets this definition.

The locations in a vehicle where Item 4A Glazing may be used are specified in S5.1.2.11, Test Procedures for Item 4A - Rigid Plastic for Use in Side Windows Rearward of the "C" Pillar. S5.1.2.11 was established in Standard No. 205 in a final rule published on August 12,

1996 (61 FR 41739, effective September 11, 1996). The preamble to the final rule explained that NHTSA decided to adopt an approach that, unlike the proposal, does not refer to any vehicle type. Instead, the approach is based on the relative location of a window in any vehicle and the occupant seats in that vehicle.

Item 4A Glazing is permitted in the following specific vehicle locations (see S5.1.2.11(a)):

(1) All areas in which Item 4 safety glazing may be used. (See S5.1.2.11(a)(1).)

(2) Any side window that meets the criteria in S5.1.2.11(a)(2)(I) and (ii). (See S5.1.2.11(a)(2).)

In reviewing "[A]ll areas in which Item 4 safety glazing may be used," we note that in ANSI Z-26.1a-1980, Item 4 Glazing is permitted in "(h) The rear windows of convertible passenger car tops." Since the vehicle depicted in your photographs is a convertible, the glazing does not meet subparagraph (h) because the glazing in the vehicle is separate from (not of the same piece as) the convertible top, and therefore is not a rear window of a convertible passenger car top.

Item 4A Glazing is also permitted in "[a]ny side window that meets the criteria in S5.1.2.11(a)(2)(I) and (ii)." Based on our observation of the photographs of the retractable glazing behind the roll bar, we would consider the glazing to be a "rear window" only, not a "side window." This is because the retractable glazing is positioned behind the roll bar in the side view, such that the view through it is obstructed by the roll bar. Since the retractable glazing is not considered to be a side window, it is not a location "that meets the criteria in S5.1.2.11(a)(2)(I) and (ii)." Since the location where you wish to place Item 4A Glazing meets neither S5.1.2.11(a)(1) nor (2), Item 4A Glazing may not be placed in the rear window.

I hope this information is helpful. If you have any specific questions about this letter, please contact Dorothy Nakama. If you have other questions about Standard No. 205, please contact Paul Atelsek. Both Ms. Nakama and Mr. Atelsek may be reached at (202) 366-2992.

John Womack
Acting Chief Counsel