You said "the dealer tells me that the car was likely rebuilt." The dealer should know for a fact that the car was rebuilt and issued a salvaged title, if not, walk away. On top of that, if the seller is slow, hesitant, or unwilling to comply with any of your requests for information about, or access to the vehicle, walk away.
The most common damage in deer related accidents is to the front bumper, fenders, and headlights, but in smaller cars the damage can easily extend to the hood, windshield, and roof. If the deer ended up on the windshield or roof, there can also be extensive interior damage. You should check under the carpets for stains or smells that the seller tried to mask or extinguish before your test drive. Be sure to check the trunk too... It's not unheard of for people to try to take the animal to the vet after the accident.
You should also ask the seller if they have any pictures of the damage. As they say, pictures are worth 1000 words, and pictures of the wreck can tell you where to look for damage or shoddy repair work. It may also show that the damage was limited to the hood, bumper, fenders, and headlights, but the body/paint work was enough to write the car off as a total loss.
Take the car on a longer test drive, being sure to include all road conditions and high/low speeds to make sure everything seems normal, and there are no excessive rattles or squeaks (2 year old cars should not have any).
In addition, have the car inspected by a certified mechanic (usually 60-100 USD). If you're in the states, the Automotive Association of America (AAA) has list of mechanics that have met their standards of service. Quality mechanics will be able to tell what mechanical parts have been damaged or replaced, and auto body shops can tell you if the frame was damaged, and how well it was repaired. They will also tell you if there is unusual tire wear (indicative of misalignment, which could be caused by residual frame damage), and the remaining life of most wear components (brakes, fluids, windshield wipers, etc).