Yes, you are encouraged to go to Kumrat Valley by your car. I had visited last year with friends on my car - Suzuki Cultus 2013 Model. You need to park your vehichle in THALL which is base of kumrat valley. One day you can visit Kumrat by hiring a jeep. If you two more days you can go Takki Banda by jeep and climb upto upper hill station Jahaz Banda and to Katora Lake.