One of the most outstanding problem in today's understanding of the Universe is the nature of the elusive dark-matter (DM) that dominates the matter content. Rotation curves have been used to put forward the concept of DM in the 70s, and have since revealed a potential problem, for the standard CDM model, on small scales (<1kpc) where DM profiles are too flat (cored) compared to predictions. Alternative DM models have been proposed to produce cores naturally. Hence, rotation curves are dark-matter laboratory given that  the shape of RC on intermediate scales (1-5kpc) is a measure of the shape of the inner DM profiles. Measuring the shape of DM profiles in distant marginally resolved galaxies (with z>0) was deemed impossible, but recently, thanks to recent innovations, it has become possible to study the shape of RCs of hundreds of distant galaxies. I will present the most recent innovations, including our recent results from the MUSE 3D spectrograph.