800 t/s are based off the F30 3-series, you can see it in the general outline, and the gauge cluster. --- Post updated --- and, the k seires is the slk/z4 of the early 2010s. as for the i series, its a e34 with the front of a audi 100, and the rear of a e24.
I think the Gavril TC83 and TC83S is based off a Freightliner FLA since i checked the IGCD page of the Truck Link: https://igcd.net/vehicle.php?id=332541 and https://igcd.net/vehicle.php?id=332543