I just finished a deal on a new 06 Sonata GLS LX. It took about 4 days to get to the point where we wanted to be, but once we sat down with the right person, and got up to leave, we got good disclosure. They showed me invoice, and I told them what I was willing to pay - adding that I would take one of the 3 cars currently in their inventory if we did the deal we wanted or we walk - which we actually did when suddenly the rep pulled in one of the approvers and then we started negotiating with the person who approved the deals. Essentially that's what you want - cut through the crud and get the decision maker at the table.
In the end, I got $750 above invoice, with PDI absorbed into the deal and a few accessories at cost. I balked at the etching fee and they promptly said the car was already done - so I said to take it off because I didn't want my vin# published for all to see - suddenly that cost went away as well. Anyway - there was no arguing, just a very business-like negotiation which in the end I am happy with. However, I found that unless you are dealing with a decision maker you will be strung along with every bit of tomfoolery they can throw at you.
BTW - I consider a block heater mandatory for much of Canada with the exception of BC. I can't tell you how many times on a frigid Ottawa morning I have just turned the crank and pulled away while more than one neighbor is unable to start because of the cold.
jww