This is true, the dents and scratches look very good, but it takes too big a bump to cause any dents and then they never get more than minor dents at that, at least in my opinion and experience anyway.
But I definitely agree, if they can keep working on this model and making damage more extensive, within the usual realisitc licensing restrictions games have to work within of course, and keep it looking as good as it does then that would be very nice.
The 175 number isn't a total car count. When you go into the car coleciton screen you'll see 175 cars with red dots on them. If you click on them you get some information about the car and the dot goes away. That 175 is just a count of how many acquired cars you have collected where you haven't clicked on them to read the info in that screen.
There's definitely a wrong count in one of the other screens though, I think this has been noticed and confirmed before, but I can't remember hich one is correct. Probably the higher number.