Have a question for the MCU team? Find the right contact information for the department you need, and get the answers you're looking for.Apply for an auto loan today with Bethpage FCU or refinance your existing auto loan to potentially lower your monthly payment. Please complete the Wire Transfer Instructions. Fill Out Online Form. Municipal Credit Union makes it easy to find affordable and flexible car loan options with member-friendly terms. Sign and submit the check to the person or firm to whom it is payable. Remember to sign the reverse side as well and please do not alter the check. Alliant Credit Union PO Box 660592. Dallas, TX 75266- 0592.