Usually not, beyond cheap, quick fixes. A dealer confirms its offer only after it sees the car in person, so big repairs rarely pay you back. Get offers on the car as it is first, then decide whether a repair is worth it.
Big jobs, like body work, a new transmission or a full set of tires, cost you cash up front. A dealer may not raise its offer by the same amount. Many dealers recondition cars through their own shops, at their own cost.
The smart move is to ask what the car is worth as-is. If a dealer tells you a repair would change its number, you can weigh that cost against the gap. Our post on whether service records help covers what to bring to the appraisal, and why the first offer isn't always the best explains why it pays to compare.
With PriceForMyTrade, you send your vehicle details in about 30 seconds. Participating local dealerships contact you directly, and first responses typically come the same day (not guaranteed). Offers are confirmed after a physical appraisal. It's free to you, and you don't have to buy another car to sell. See how competing offers work.
Want to know what it's worth as-is? Get competing offers.