I'm not sure I get all this. Is it something to do with not wanting people to know you're driving a hybrid? Or is this just a general feeling of 'my car shouldn't be a billboard for the manufacturer?'

If you just want to take off the logos and insignia etc. because you think of it like taking off the product packaging when you buy something, that's one thing, (personally I think everyone should get rid of those tacky license plate holders that advertise the dealership- they just cover up part of the plates and look awful) but if you're actively disclaiming the hybrid part of the product packaging, then I'd be interested to hear your motives. Ashamed of your hybrid? Or something else?