Maximilian Karl mourned her death greatly and constructed the Neo-Gothic mausoleum at St. Emmeram's Abbey for her.

Maximilian Karl married secondly to Princess Mathilde Sophie of Oettingen-Oettingen and Oettingen-Spielberg, daughter of Johannes Aloysius III, Prince of Oettingen-Oettingen and Oettingen-Spielberg and his wife Princess Amalie Auguste of Wrede, on 24 January 1839 in Oettingen in Bayern.

[4] Maximilian Karl and Mathilde Sophie had twelve children: In 1843, Maximilian Karl and his family moved to the newly constructed Donaustauf palace of the Thurn and Taxis family in Donaustauf, which was completed in the same year as the nearby Walhalla.

In 1827, Maximilian Karl was his father's successor as head of the private Thurn-und-Taxis-Post which had its headquarters in Frankfurt am Main.

With the annexation of the Free City of Frankfurt by the Kingdom of Prussia in 1866 and the forced sale of Thurn-und-Taxis-Post for three million Thalers ended the era of the Thurn and Taxis family's postal monopoly.