To rid an area of spiders, simply mix 4 tablespoons of coconut oil with 8 ounces of white vinegar and put into any spray type bottle and spray.
Wal-mart has a 31 ounce container of coconut for less than $10.00.
Coconut oil is usually in a solid form, so you will need to microwave a few seconds to melt it and use up right away or it might plug up your applicator bottle.
your car will smell nice and no spider will ever crawl in there again.
Do it every four months for year round protection.
Can also be done in the home/apartment, garage, shed, whatever and wherever you don't want spiders.
Roll up the windows, close it up tight. Open the door and toss an aerosol bug "bomb" in. Open it up next morning and let it air out a couple of hrs before driving. Good luck!
If it's not too expensive, you could try having your car detailed.
Larry has a good suggestion, I'd do what he said, then vacuum it getting every nook and cranny you can.
I bought a car about two months ago. I think it was just sitting in a garage for a while before I bought it. Everything was going good until a week ago when I found a spider crawling on the inside of my windscreen, then another then another. Yesterday one fell on my lap when I was driving and I'm absolutely terrified of them and nearly crashed. When I got home I hoovered every inch of my car thinking that would get rid of my problem but today my passenger had two spiders crawl over him when I was driving. I can't seem to find any advice on google on how to get rid of them? I don't park my car under any trees or near bushes. They're all different sizes and I can't see where they're coming from. Someone please help!!!