I go to a mom and pop dealer in my town. I am a no-haggle person in all types of transactions, so if I don't like a price, I just go elsewhere. I don't ask for any of the things listed here. My first one, I mentioned that I needed to run to the store to get the right size hitch ball, and he put one of his on for free. That was about it for freebies.
But...I take it in every year at the end of the season for winterizing and a checkup. It is done as soon as I hit the lot, so I can take it back with me instead of leaving for several days. Everything is gone over. Often a small item like a fuse is replaced with a "don't worry about it" attitude when I try to pay them for their time. They have caught big issues before they become bigger issues, too, so I take my TT back home knowing it is in good shape for the next season.
I did not consider going any place else for my second TT, and will go back it I decide on a next one. Service after the sale is worth more to me, and I like supporting a small business.
