1907 American Underslung sells for $1.43 million, the most ever spent for an AU. This one was

This particular American Underslung Roadster was purchased new by Frank “F.C.” Deemer, a successful businessman who’d amassed a humble fortune in the oil and gas business. So impressed was Deemer with the Underslung Roadster that he opted to use the car for his honeymoon

It was later bought by Dick Teague who had a particular love for the American Underslung, he told his fiancee Marian he would marry her if she found him one

https://www.hemmings.com/blog/2014/10/08/1907-american-underslung-sells-for-1-43-million-setting-record-for-the-marque/