Rolling out of your driveway every morning with a full battery changes how you feel about driving electric. You skip the gas station entirely, and charging at home overnight usually costs a fraction of public fast charging. Prices on hardware tend to dip around major holiday sales and Earth Day in April, giving you a bit of leverage on the gear itself.
Before you talk about payment terms, pin down your installation costs with a local electrician and check for utility rebates. Dealers and installers rarely bundle the wiring work into the hardware price, so treat negotiation and financing as two totally separate conversations.
Remember that the intro window is a deadline, not free money. If you still have a remaining balance when those 18 months end, standard interest rates will kick in on whatever is left over.