16" x 13" Cat Spike Mat Outdoor Indoor Cat Deterrent Scat Mat Keep Cats/Dogs Off Counter Pet Deterrent Training Mats Plastic Mats with Spikes (18.3 Sq.ft) (10)

We use spike sheets in the house, you may be able to deter them if you put them on top of your car: https://www.amazon.com/Deterrent-Outdoor-Counter-Training-Supplies/dp/B0C1T62X5C/ref=mp_s_a_1_1_sspa You also may be able to redirect them if you put out cardboard scratching pads. The deterrents often work, but redirecting them is a good second line of defense in case they defy your will