Hi. For about the past month, I’ve been finding a web behind my left front tire when I go out to my car in the morning. About two weeks in, I came outside to find the spider feeding (ick!) on some sort of caterpillar. The spider was big, but it dashed back before I could get a good look, so I’m left with the impression that it’s one of the ones you really don’t want near you. When I open my car’s front door, I can see a gap between the wheel well and the door frame, which I guess leads to the area behind the gas pedal, and it’s apparently hiding in there. I called my car repair place; they said call a pest control company; pest control said they didn’t handle cars and to get the car detailed. I called a car detailer and found out most of what they do wouldn’t help, but I’ve taken it to their car wash three times and each time had them vacuum out that crevice. In each case a web reappears a couple of days later. I’ve found spider repellant recipes which appear to make the spider move for a few days, but it comes right back, and last week I found another caterpillar in the web. I’m sensitive to pesticides and hesitate to spray one with my door open (and in response to the one thread I found when searching, I don’t have access to a closed garage where I can set off a bug fogger). Other than staking out my car in the predawn hours, ready to smash the sucker, how do I get rid of this thing??
I’m assuming you’re in the U.S., if so what state? How big in terms of measurement is this spider if we’re talking about inches. Is this spider bigger/wider than a pack of cigarettes?
Unless it is some sort of giant tropical spider, setting out some of those sticky spider traps placed in it’s usual haunts should get it. Although then you have to deal with disposing of it.
Ha! California. I couldn’t get too good a look at the spider as it kind of blended in with the web. Shape-wise I was wondering if it might be a brown widow, but I’m not sure (only saw the top). I really hope I’m wrong. The web I destroyed this morning snapped audibly; tough material!
Oooo, I didn’t know those traps existed! I’ll try to find some! Hey, as long as it’s glued to those traps, I can sweep it into a bag or something. Cool!
soak the area with an instant killer.
I would be concerned what an insecticide could to to paint. You especially don’t want to lose paint in crevices, else you’ll get rust.
http://nature.berkeley.edu/~stevelew/cbcstuff/common_spiders/big_spi_quilt.html
The link above shows spiders common to Cali. Apparently only the black widow is significantly poisonous. There is a brown or false black widow listed and it does not appear to be dangerous to you. If the are you think the spider is hiding in drains well, you might try putting a garden hose in there and turn on the water. It might drown or wash away.
I usually leave spiders (and snakes) alone. They are predators and keep a check on other pests I like less. But one less spider won’t destroy the balance of the world.
There’s also the issue of the fumes getting into the car, too. The only way I can see into that crevice is by opening the door.
The area probably drains okay, but it may also lead to areas I dn’t want to get wet (brake and gas pedals?)-- I don’t quite know how to describe it. As for leaving it alone, I’m just really tired of coming outside and thinking someone’s thrown shrimp at my car. Those red caterpillars I found in the webs are gross. 
When a spider web snaps audibly you’ve probably got a black widow. We have lots of them where we live (Eastern Sierra, Calif). I’ve never seen one dining on a caterpillar, though. They do reproduce prodigiously, so you’ll want to take care of the situation. I would saturate the area with insecticide, with the car and surrounding area well vented. I think insecticides are flammable, so take precautions. You might want to contact your local UC Extension, or county agricultural office, for further advice.
The time I did see the spider I could tell it wasn’t black. It was grayish-brown and blended in with the web even though it was on top of the web. It also looked to be a “grown-up” size (baby spiders can often be different colors than their adult versions). The agricultural office is an option, though.
“Caterpillar” is the only name I can think of for what was in the web. It was red, no hair, but looked like a big caterpillar you might find on a plant.
Update! Thanks for all the replies. I called the county agricultural office and spoke with an entymologist. She said that while she couldn’t identify the spider without actually seeing it, she’s pretty sure based on my description that it is NOT a black or brown widow. She said those two do not move very fast and hate movement, so if what I saw was speedy and living in a car that’s seen daily movement and lots of car washes/vacuuming, it’s probably something else. She thought it was most likely either a common house spider or a jumping spider. Both are harmless and have lifespans of only a few weeks. (And from a link in one of the replies, the pictures of house spiders show a large abdomen similar to widows in shape.) So other than annoyance, I should be fine.
Connect a hose to your exhaust pipe and the other end through a partially opened window and seal off the rest of that window with duct tape. Start the engine - GET OUT OF THE CAR - and let the fumes fill the car for 20 minutes. Then hold your breath, open the driver side door, get in, shut the engine off - GET OUT OFF THE CAR - open up all the other doors and air the car out for 20 minutes. Repeat if necessary.