The best way to get rid of roaches in your car would be getting Ridsect Cockroach Killer 1-s, Its an aerosol based insecticide that not only kills but leaves residuals that can last up for about 3 months or so. With its imipothrin based, it is one of the most user friendly and effective killer in town for those roaches. I would not advise you to use the baits as its not as fast kill and it dies while hiding so it will be difficult to find their carcass. Don't worry this aerosol smells like talcum powder... but i would not advise you to inhale it as it has a small level of toxicity. Just follow the instruction and you will be fine.
Just a thought, cockroaches live in your car because of your seats and other upholstery that is made of husks (ie your seats cushions), therefore the longer you keep there the more 'bucket' your seat will be.... as it will sulk at the base.
Pandan leave is just a perception that roaches dislikes them, similarly to to flies and candles. Roaches actually feed on these pandan leaves as well...
