I found this when I googled the sweepstakes, so it looks pretty legit that they e-mailed you..Congrats again!
7. Verification of Potential Winners: Potential winners must continue to comply with all terms and conditions of these Official Rules, and winning is contingent upon fulfilling all requirements. The potential Sweepstakes Grand Prize winner will be notified by email, telephone, or registered mail after the date of random drawing. The potential Sweepstakes Grand Prize winner (parent/legal guardian if winner is a minor in his/her state of residence) will be required to sign and return to Sponsor, within ten (10) days of the date notice or attempted notice is sent, an Affidavit of Eligibility, Liability & Publicity Release in order to claim his/her prize. If a potential winner of any prize cannot be contacted, or fails to sign and return the Affidavit of Eligibility, Liability and Publicity Release within the required time period (if applicable), potential winner forfeits prize. In the event that a potential winner of the any prize is disqualified for any reason, Sponsor will award the applicable prize to an alternate winner by random drawing from among all remaining eligible entries. There will be three (3) alternate drawings after which the prize will remain unawarded. Prizes will be fulfilled approximately 8-10 weeks after the conclusion of the Promotion.
8. Prizes:
a. Sweepstakes prize: ONE (1) GRAND PRIZE: 2007 Toyota Camry CE. Sponsor will determine all features of automobile including but not limited to color of exterior and interior, and all other features or upgrades will be allowed only if permitted by delivery dealer and paid for by winner. Winner must be a licensed driver and will be required to provide proof of insurance at time of delivery. Winner is responsible for title, license, registration, dealer preparation costs, auto insurance and other fees associated with prize. Winner must take delivery of prize from the automobile dealership designated by Sponsor. Approximate Retail Value (ARV): $20,000. Odds of winning the Sweepstakes prize depend on the number of eligible entries received during the Promotion Period.