Whoever you spoke to from Suzuki from whatever department was correct. If you were using their logo or close-to-exact model name and font that is, strictly speaking, trademark infringement. No question about that. Also, if you are selling anything whatsoever, however small, that would constitute trademark dilution. If the use of the mark is non-commercial, no dilution. Usually.
You of course did the morally corect thing in asking permission to use their mark, but there is no way in hell they could ever grant you that right. Think about it. In fact, once the mark holder becomes aware of potential infringement or dilution, he is obligated to act against that infringement or dilution, or he risks losing the rights to the mark altogether.
Having said that, there are web sites like this all over the internet that use exact logos and sell mugs and tee-shirts and whatnot and the mark holders don't do a **** thing about it. You mentioned the guy from Suzuki had visited here before. I assume he saw the logo, yet was he going to be intiating any enforcement? I doubt it. In a sense your request may have forced their hand to ensure compliance here, but, again, you did the right thing.
FWIW.
Peace.