For traditional car rentals inside the US, these are my personal tricks & strategies (some also mentioned in other posts; can’t comment on Turo/Truro? as I’ve not yet tried it, although it looked interesting):
(Fair warning: may be tl:dr for some)
- Sign up for a loyalty account with each of the major & secondary car rental companies. It’s free, & it’s how you’ll qualify for their discounted rates. (Many of these deals only work for less than a month’s rental, however, so you may need to book, return & re-up on a 2nd reservation partway through.) Also note that most deals require you to return to the same location, unless it’s specified as a one-way special like the repositioning rentals mentioned by others. Another tip on special rates: the phone apps often don’t list or let you book the available deals; sometimes these are only viewable & bookable on the full website (looking at you, Hertz.)
- Invest in AAA membership. It provides 10-20% discounts (& sometimes really excellent ones like 35%) to Hertz, as well as the ability to add a second driver for free — and drivers under 25 with a AAA card don’t pay the “young driver” penalty. Extra discounts on hotels & other useful travel sites as well, plus free roadside assistance that can be faster than calling the rental car company at times.
- Check your CC benefits for any rental car insurance they may provide. For instance: once it’s set up on your account via a phone call with them, AmEx Platinum gives extensive damage coverage for a flat $25 fee per rental if you pay with the card. (Certain countries excepted, like Ireland - but works in the US & most of the UK.)
- Reserve as early as possible to make sure you have a car — but I never pay in advance in case my plans change. Instead, make sure the reservation is cancelable. Check back each week, as often the prices will drop significantly week-by-week as the dates get closer if they still have a decent amount of inventory. Plus, sometimes new specials get posted. (See a better price? Book the new reservation, THEN cancel the old one.) Be sure to check different car sizes too…sometimes a mini- or mid-SUV becomes cheaper because they have more of them than mid-size cars available that week.
- Wherever possible, check for rental locations in the city or nearby towns instead of on/off airport or train stations. Rates are almost always lower, & you skip the extra taxes & fees imposed for on-airport locations. That Uber/Lyft to the alternate location could save you hundreds or more for a long rental around holidays.
- Some rental car companies offer special pricing for longer-term rentals (I believe Enterprise is one, also possibly Sixt?) — but often you need to call their local office to ask about it…it’s not always built into the online booking site or app rates.
- Tolls: be SURE to ask about toll coverage costs in advance, in areas that use them heavily. Most rental companies at airports charge usurious daily rates for use of a toll transponder, PLUS the fees for the actual tolls you encounter — while an Enterprise in the city/town simply charged me for the actual tolls I went through…no service charges or transponder rental required. In some states (Florida for one), I bought my own SunPass transponder for maybe $15 at a local pharmacy/bodega before hitting the rental office, & created an online account with $20 in it, set to auto-top-up by $10 if it ran low. When I got my rental, I added its license plate # to my account & affixed the transponder to the windshield…all set. Now I carry it with me whenever I travel to Florida, & just update the rental’s license plate number on my Sunpass account page.
- On occasion, it can be cheaper for the car if you bundle it with your flight and/or hotel…but tbh, my best deals come from the other strategies I listed above. (AND I can deal directly with the rental company if something changes or goes wrong.) But it’s worth checking to see.
Good luck; hopefully some of that will be helpful 