My car doesn’t get cold air in the back my toddlers always hot

I’m wondering what I should do about this. He’s 20 months so I still have the car seat rear facing as I live in Ontario, Canada and they say it’s best to keep them rear facing as long as you can.

Should I put him forward facing so the vents at least go in his direction? I literally want to buy another car because of it. I feel so bad for him! I’m pregnant with baby number two so I’m worried about that.