The 1,000 free Airberlin Topbonus miles for merely registering with the German car rental company Sixt has returned.
All you need to do is to open a Sixt account and link it to your Topbonus account in June and the miles are then deposited to your account.
You can access this offer on Sixt’s website here.
Note that there are some bonus miles and discount offers for Airberlin Topbonus members that rent with Sixt.
I did this offer last year and the 1,000 free Topbonus miles were shortly deposited to my account.