This usage of too is an example of understatement. It occurs only with verbs in the negative.
My mother wasn't too pleased about the mess in the kitchen.
Variants with the same meaning are to be "none too pleased" and not to be "any too pleased."
"Too" in this sentence is being used as "very". This is one of the meanings that "too" can have in a sentence, functioning as an adverb. In this sentence, it is clear that the subject of the sentence is not very appreciative of the car - the sentence is also correct without "too", but a little less idiomatic.
If you would like to stick as closely to your proposed slogan as possible, I would suggest altering it slightly to
Makes a difference
This links nicely to your second bullet point in that it is clear that wearing it will have a positive effect on the consumer.
Your current phrasing is more like a command to someone else that they should make 'it' ...