True many plasticizers used for PVC such as dibutyl phthalate, dioctyl phthalate and diisooctyl phthalate have an odour, but it does dissipate with time. I haven’t worked with PVC formulations for a long time, but there are clear odourless plasticisers available now such as epoxidised soy bean oil, which has a light yellowish color. There are others and Eastman have a proprietary colourless and odourless plasticiser: Eastman 168. Price will presumably be an issue and cheaper types that are not suitable for food applications should suffice. Formulations will have to take into account where the market is with temperatures in some countries even going outside of -40º C to +40º C range.
I have been using various types of rubber and flexible vinyl floor mats in my cars for more than 20 years and presently have clear vinyl mats in one of my cars. Some dealers often supply cheap black rubber ones with new cars, but they smell too much and the smell persists for months. Paper or thin PE ones are sometimes used by service stations to avoid dirtying the customer’s mats during servicing. Assuming we are talking about regular mats to be bought by car owners, there are many choices available in shops stocking automotive accessories and most seem to be rubber or flexible vinyl, which may be clear or pigmented. I am puzzled by the suggestion of so many materials, which would not fit the flexibility requirement and/or are relatively high-priced compared to vinyl. If I am not missing something, the issue here would appear to be how to formulate a clear flexible vinyl compound, perhaps starting with DOP and a suitable stabilizer. Since this is not a food-related product, I presume the choice is open for organic, metal or organo-metallic stabilizers.