I used one of these at university because I had the same issue of just one specific window always having condensation. You just buy the refill discs and I think it looks ok, nothing special but not an eyesore!
I've a long illustrious career with shitboxes and this used to happen an awful lot when me and friends were in college. Your experience may vary but we found it was due to seals getting older and water (or even just "moisture") coming in to the car and getting in the soft furnishings. We found that filling the car with a couple of dehumidifier products worked perfectly.
Options are:
I'd advise buying two of the UniBond, a couple of additional refills, then: making sure they stay upright when driving; and empty them every couple of days. I've found the "pucks" in there last ~2-4 weeks.
Maybe try putting it in a cabinet in a room where you can keep the windows closed, and then sit this next to it. Then get an extra long HDMI cable to bring the image into your living room? The controllers should work at 10m away, and if you get your games digitally, then swapping disks wont be a huge issue. Might cost a little for the cable though... and require a lot of messing about getting the cable through the house... You could always just try the device in the PS4's current location?
Check to see if there is water trapped in the car, like the spare wheel well. If water is there then it's just going to keep condensing.
If you've got a dehumidifier small enough to fit the car then use it. If not, this is supposed to be good if you're on a budget: https://www.amazon.co.uk/Moisture-ultra-absorbent-dehumidifier-condensation-refillable/dp/B00F1DNYPE
My Peugeot 107 has water ingress, I've got two Pingu bean bags (or whatever they're called) and I can't say they've kept the windscreen from condensing. But it's not making it worse either.
Honestly, a dehumidifier is a solid investment. I had a lot of humidity and damp issues in my place and a dehumidifier sorted it.
If you did want to go the cheapest route, these portable units are really good. I have one in my boat and it works well. Keep in mind you do have to keep buying refills for it though. Another little superstar I've used are these disposable dehumidifiers.
Open the window to ventilate when you can, especially if you're drying clothes in that room.
I've bought a couple of these from amazon as well - https://www.amazon.co.uk/dp/B00F1DNYPE/ref=cm_sw_em_r_mt_dp_U_-pApEbQVTJGQA
Cheaper than an electric dehumidifier and they do a pretty decent job
Sorry, already replied above, but try this: https://www.amazon.co.uk/UniBond-Aero-360-Moisture-Absorber-Device/dp/B00F1DNYPE
Get aero pure 360 dehumidifier for time being they work well not sure If you're in UK but here's a link
http://www.amazon.co.uk/UniBond-1807937-Aero-360-Moisture-Absorber/dp/B00F1DNYPE