I would suggest at least getting some foam blocks. There are kits specially made for securing kayaks that aren’t too expensive.
Example: WOOWAVE Kayak Carrier Deluxe Carrier Kit Universal Soft Standard Foam Block for Roof Racks Car-Top Replacement with Tie-Downs, 12 inches https://www.amazon.com/dp/B0855JQ2MS/ref=cm_sw_r_cp_api_i_VWBJBEJHKJEX27XAVME1
This is the way.
I have a jeep grand cherokee. I can drive 1 hr to various places in Florida with my Kayak on the roof with a foam carrying system. I am looking into racks because as this commenter suggested, you have to do it right or else you get a horrible noise going down the road, also I use ratchet straps instead of the garbage straps mine came with. Another problem is the straps cutting into the kayak, but I probably did it wrong.