I did something similar that was a great hit with my maintenance plan clients. It was set up as a "goody bag" or "care envelope" in custom black booklet envelopes. They had slots for business cards on the flap, our logo and contact info in gold, and made of sturdy textured black plastic.
Inside I put:
Our Trifold, a care trifold for general maintenance between details, a prepaid and addressed post card appointment mailer with the next recommended detail date on it for scheduling (20% off next detail if returned by that date), a microfiber, three referral postcards (10% off next detail, use within a year) with the original clients account number for reference, and a personal thank you card, and their detailed invoice.
I can't for the life of me find where they were made because I'd like to use them again in the future. Clients loved using the post cards to schedule their appointments as we received many of them back within 6 months. Most of the vehicles even had the envelopes still in their glove box. Some clients returned the envelope with their own business cards in the slot.
Very professional and effective marketing if used correctly.
