As automakers work to reduce emissions—and the carbon impact of driving—by electrifying their vehicles, the environmental impact of the rest of a car becomes more significant. Audi has joined a growing list of manufacturers looking to mitigate this by using more sustainable materials for car interiors.

The effort covers not only the electric E-Tron models, but mainstream vehicles as well.

Up to 89% of the fabric in the current A3 compact is made from recycled PET (polyethylene terephthalate)  plastic bottles, according to Audi. The plastic is turned into a yarn that can then be weaved to mimic the look of conventional textile fabrics.

Audi said up to 45 PET bottles are used to make seat fabric, while an additional 62 recycled bottles go into the A3's carpets.

The percentage of recycled materials used will "rise considerably" in the coming years, Audi said.

One goal is to make seat upholstery completely out of recycled materials. Certain areas are proving challenging to convert, but engineers are working on replacing all existing materials with recyclable polyester, Ute Grönheim, head of materials development at Audi's textile division, said in a statement.

Audi also wants to make upholstery entirely from "unmixed material" so it can be recycled again after a car has reached the end of its lifespan, Grönheim said.

2020 Audi A3

Other automakers have dabbled in recycled materials as well. Nissan began using recycled PET plastic in the first-generation Leaf, while the original Fisker Karma was available with a sustainably-sourced leather interior. More recently, Polestar has said it will use recycled and sustainable materials in future models, including a new fiber-based material made from flax as well as recycled plastic.

But seat upholstery and interior trim may not be the only automotive uses for discarded plastic bottles.

Los Angeles has proposed paving its streets with recycled plastic, although the material would be mixed with asphalt.