Marketplace
HARMAN3M
Previous 4 months coupon (https://www.cheapies.nz/node/13943) expired and here is the best I could find. This link looks like came from https://www.jbl.com/googleplay.html but don't need registration.
As usual, might only work for new users. Also, https://www.cheapies.nz/node/8817 is working again too but this is one month longer.
According to T&C below, this link is valid until the midnight on 31 December 2019.
http://www.harman.com/sites/default/files/HarmanTermsandCond…
Offer only available to customers who are not current Google Play Music subscribers, have not been Google Play Music subscribers nor participated in a Google Play Music trial in the past 12 months.