I often have spider webs on my right side mirror and in the handle to open my boot. I've seen a spider on the boot handle once, but when I tried to catch it, it crawled inside the handle somewhere (difficult to see, as it's one of those handles that's under the logo). I'm pretty sure the spider/s are still there, as even after cleaning the webs away, they come back soon.
I've never actually seen a spider inside the car (i.e. where the driver and passengers sit), and no webs inside either, so I'm guessing the spiders are inside the mirror / handle.
The car is a Hyundai i30.