There are trainers that let you change the resolution, which will fix the cars and background, but the on screen gauges and text will still be stretched. Here's one for version 1.2 and 1.3. I don't know if there's one for version 1.4:
Some video card + monitor combinations let you view a 4:3 image or a smaller image on a 16:9 or 16:10 screen by using black bars on the sides. The terminolgy for this in the setup menu of you video card or monitor might include the terms aspect ratio, square pixels, or letterbox.
I've used a generic game trainer to do this by alt-tabbing out ot the game, and using the trainer to modify memory. There are 7 locations for width and another 7 for height, all 4 byte values, and located in the range hex A00000 -> BFFFFF.