I live in Taiwan and have a domestic 2008 Accord. It never lost its "new car smell" and in fact the chemical smell has increased. It almost hurts the eyes. I spoke with dealer about this who says it is mold in the air con, but this is not a mold smell: I am sure it is some sort of gas being emitted by some plastic of some sort. Any one ever hear anything like this?
Thanks
Ben

 

Can't say that I have. You might try changing the cabin air filter, if someone sprayed it with "something" that might be the source.....I'm way out on a limb with this.

 

Some things to check:

1) Losing any coolant? If yes, there may be a heater core leak in the cabin. Coolant has a chemical smell that is distinctive.

2) A/C leak. The lubricant (PAG) used by Honda AC has a very noticeable chemical smell in small quantities. If AC performance declines, this is a distinct possibility. Leak would be in evaporator core or expansion valve area.

3) Finally, try to find someone else w/ same car and see if there's any difference. You may be sensitive to the plastics that outgas under heat and age.

good luck