I seem to have fumes entering the cabin and am unable to figure out where they are coming from. The symptoms are that I get a scratchy throat, cough, phlegm and sometimes a little lightheaded when or after I drive. I've had the exhaust checked out twice (3 times counting state inspection) as that was the initial suspect. I've replaced the tailgate seal (it's a wagon) and even put an extension on the tailpipe to get it past the bumper. I have completely cleaned out the flame trap system and replaced the oil cap seal and valve cover seal (they used to leak). Maybe the rear main seal leaks and it gets to the exhaust, but I don't lose much oil ~ 1.5 qt per 5,000 miles. Where else have people discovered noxious fumes? I don't really smell anything consistently, but maybe catch a slight burning smell occasionally. Nothing obvious like tailpipe fumes. What am I missing? Are there certain electrical connections that are prone to overheating and burning plastic? I discovered one such case recently at the headlight relay, but fixing it didn't eliminate the scratchy throat. It seems to be worst with the windows down and around town driving.
Please help with suggestions, I really need to get this fixed!
Thanks,

Tom
'86 245 DL, 251k miles