You may be allergic to mold. Car's 20 years or so old. Dizziness, sore throat, etc is consistent with symptoms of sick building syndrome, a common cause of lawsuits in the construction industry caused by putting vapor barrier on both sides of an exterior wall when it should only be applied to the outside only, ensuring mold proliferation in the wall cavity. Contractors and developers and architects get sued for big money over this on a daily basis. It's very unhealthy so don't neglect the mold thing. Unless you smell a distinct mix of burned/unburned hydrocarbons for sure don't assume it's exhaust that's making you ill.

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