First of all, welcome.
You have to check inside the object node for links to various textures. It looks like some are missing. TG doesn't import all perfectly yet.
Then; if you need really transparent glass, you'll need to add a glass shader to the part in your car, not the default shader that's now attached.
For reflection of the car body, you'll have to add a reflective shader set to RayTraced (which is default) between part and defaults hader that contains the color/texture, but you should also change the refraction index to one for metallic (higher). There are some tgc's around that you may find usefull. Just use the search function for metallic or something.
Tires' default shader may also need a darker color and perhaps a dull reflection (no-RT), experiment with values.