Second hand smoke will never show up in a piss test. it is only detectable in urine after a pattern of use. Even a first time smoker, who actually gets high, will not have detectable levels of THC in their urine right after they toke. Unless your job does blood or hair testing, which is much too expensive for employers, you will never piss hot for THC even sitting in a hot boxed car. But, if you were a regular smoker and quit, it will show up in urine for a long, long time. And levels can increase with exercise, especially if you're fat.