Looks like this thread was resurrected from the dead (10/2021). Interest rates have changed drastically. Right now, about 5% is good with a local credit union or bank trying to earn your business. Other less hungry places may be 7-8%. All assuming good credit of course.
I saw Ford had 0% offers up to 36 months, but that was limited to Explorer XLT models.
I mention the rates because adding lots of small things also means a bigger payment and paying more interest. More importantly, it raises your loan to vehicle ratio. Most people try to put $0 down, or as little as possible. So when you start rolling things into the loan like tint, bed cover, warranties, tag/title/taxes, negative equity, adjusted dealer markups (ADM's), etc it's easy to supersede 100% of the vehicle value.
Each bank has their own policies regarding loan values, but generally speaking 100%+ values are considered riskier than those < 100%. The more perceived risk the bank takes, the higher the interest rate. And the wheel goes round & round.
All that to say that adding stuff into the loan is not really advantageous for the long term from a financial perspective. Maybe if you are getting 0% it can be justified to a point, but when you start staying at 100% loan value or creeping over, you should also consider paying for GAP coverage so that if you total your vehicle prior to having it paid off (or at least to a break-even level), you will have some protection and not get caught upside down.
I'd add stuff like tint and other accessories later via a 3rd party and pay cash. You remove the dealer from the equation and likely get better quality and lower markups/prices as well. Plus it's good to feel the pain of paying the cash -- it keeps your upgrades in perspective and from overspending.
