This depends on the type of reimbursement you are receiving. If you are being paid the IRS reimbursement rate, you don't have to register your car. You just have to enter your mileage in the format your company prefers (daily, weekly, etc) and it will reimburse at the rate set for your company (usually IRS).
If you are on a FAVR program and have a specific rate per mile, then your admin must first load in your rate in the main car reimbursement settings. Then you would register your vehicle by selecting company car from your profile, selecting "new", adding the info, marking it preferred and then saving. You would select the correct mileage reimbursement expense type and complete the info.
@Bede I'm guessing you are located outside the U.S. as most other countries use the word "claim" instead of report. 🙂
Log in to SAP Concur. Click Profile near the upper right. Select Profile Settings. On the left side of the Profile Settings screen, click Personal Car found under Expense Settings. Click New, fill out the details.
When you create your expense claim, you'll select Personal Car Mileage as the expense type. Your company may have renamed the Mileage expense type, but it should be something similar to Personal Car Mileage. When you fill out the details, you will see a Distance field to enter the total of miles or kilometers driven.