Does anyone know (or do any of these buying guides ever say) if when
negotiating for a new vehicle, if an offer to outright buy the vehicle
(check, bank draft, credit-card, etc) is seen by the dealership as more
(or less) desirable vs the typical way most people buy cars (long term
payment plan). ?

I mean, if you have the means (and inclination) to fork over the full
purchase price for a new vehicle, does that work in your favor when
negotiating the price, or would the dealer (or his financing company)
rather bleed you for $300 - $700 a month for 5 years?

I negotiated to have my purchase go through 100% on my credit card when
I bought my '2000 Chrysler 300m back in the fall of 1999. After I
signed the deal, they came back and said that they can't do it because
they didn't anticipate the Visa transaction cost of putting such a large
purchase through. I balked and said they signed the deal, but
eventually settled and met them half way on the transaction cost. I got
a ****-load of frequent-flyer miles because of that purchase.