On my Swift GTi - which probably used cheaper plastic - I found that a careful but generous application of Meguiar's #7 Heavy-Cut Cleaner followed up with hand buffing and a wee bit of rubbing compound worked just as well, and lasted nearly a year.
Something to try.
__________________
:: :ToDspin: - supermod
- but who gives a shit?
:: HAN Integra FAQ: If, by some miracle, yours hasn't been stolen... check it out!