many thanks 有这样说法吗?

没有，只见过thanks a lot或者thanks a million.

有。常用！

thanks a lot
thanks.
many thanks .不经常用

有的

可以这样说，表示非常感谢的意思

有，是多谢的意思

有，等同于非常感谢

Yes.

UK written Many thanks.'
UK written Many thanks to so many parents who are sending voluntary contributions towards children's instrumental lessons.
UK written To ease overcrowding at Castle Court, the decision was take to locate the design team in the Highways Depot at Stilton, using spare office space that had become available due to the DLO re-organisation (many thanks to Stuart Ad Mans and his staff of West Highways Division for their co-operation).
UK written Many thanks to those parents who have contacted us, we are happy to hear from you with compliments and concerns.
UK written Many thanks for your letter which was dated 2nd August and for your card from Rhue.
UK written Love you all very much, thanks for being there for me when I've needed you.
UK written Many thanks to Richard Stott for reminding us of the scandalous treatment our servicemen received during this period.
US written It was accompanied by a note: `Many thanks for your nice letter and the lovely pictures.
US written Many thanks to all who made this possible.
US written Many thanks to the members for their generosity and their eagerness to support the next generation of theatre artists, administrators and technicians.
US spoken I've received so many thanks.
(c) HarperCollins Publishers.

mang thanks等于thanks a lot 或者thank you very much
是比较口语化的一种