How to Treat German Cockroaches in Cars
Cars are really hard to treat. The first thing you should do is make sure that you do not park in a garage. Parking in a garage will allow the cockroaches the opportunity to infest the house.
Naturally, you want to start by thoroughly cleaning the car. Make sure that any food wrappers, crumbs, and so forth are removed. That means you need to vacuum really well. You should have a strict rule that nobody ever eats in your car, including you.
Next, you want to spray Nibor-D every place where it will not be noticed. You can spray it under the seats, in different places under the hood, and the entire trunk. Spray it everywhere that it will not be seen or will not damage anything.
After that, see if you can puff some diatomaceous earth into the doors. This can sometimes be accomplished by inserting the duster where the windows meet the doors. There's usually a seal right there where you may be able to insert the duster tip.
Place an IGR disc under one of the seats, one in the trunk, and one someplace under the hood. Replace them every 90 days.
Apply a bait every place where it will not be seen. Just use small dots and space them about 12 inches (30 cm) apart and use a different formulation of bait every 90 days. Domyown.com has a good selection of gel baits. Try to get four different baits, with different active ingredients.
In the summer months, always park your car in the sun, with all the windows shut because roaches do not survive well at high temperatures. You can also put an electric heater in the car to boost up the temperature even more. If you can get the temperature over 120 degrees Fahrenheit or 49 degrees Celsius, for several hours, that may do the trick. If you live in a cold climate, then you always want to keep the car outside because roaches do not survive well in cold either.
German cockroaches are hitchhikers, so be careful that you do not bring them into the homes of friends and family members. They will get into anything you have in the car, and they will attach themselves to your clothing.
IGR disks: https://www.domyown.com/gentrol-point-source-p-51.html?pdpv=2
Diatomaceous earth: https://www.amazon.com/Harris-Diatomaceous-Earth-Food-Grade/dp/B06X952WC5/ref=sr_1_7?
Nibor-D: https://www.domyown.com/nibord-insecticide-p-2410.html?pdpv=2