To help those who will search for this over time. A Brompton just about fits in the ND series MX5 which is smaller than the previous NC MX5. Saddle and tall seat post had to come out. Small (non Brompton) rack is still on. It is a 2003 SWB Brompton, I’ll try a more recent one later. Bonus, room leftover for a toothbrush!
by Zakmackraken