Keepin' it clean - ideas?
 

Looking for help for good cleaning products for the plastic on our cars.

Was cleaning my pearl white this weekend and noticed the rear bumper had a definite baked on greyish tinge to it - only really noticeable when you're up close. The only thing I had that could make a dent in cleaning it was some petroleum based cleaner/wax - and even that took a lot of elbow grease! I'm guessing it is the same stuff that collects on the plastic bumper around the exhaust tips, just not as bad. Anyone got any good advise on how to clean this stuff off - looking for easy and safe for the plastic!

Similar problem with the plastic lower body cladding - road grime seems to get right into the plastic and no amount of washing or scrubbing gets it out - any suggestions!

Thanks in advance!