Here is one example of one I remember having troubles. see attached letter from DMV.
http://germancarsforsaleblog.com/1973-bmw-1600-touring/
http://m.ebay.com/itm/181991165764?rmvSB=true&ul_ref=http%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-53200-19255-0%2F1%3Ficep_ff3%3D2%26pub%3D5574776666%26toolid%3D10001%26campid%3D5336180819%26customid%3DCarter%20Johnson_1973%20BMW%201600%20Touring_2016-01%26icep_item%3D181991165764%26ipn%3Dpsmain%26icep_vectorid%3D229466%26kwid%3D902099%26mtid%3D824%26kw%3Dlg%26srcrot%3D711-53200-19255-0%26rvr_id%3D1261229593646&_mwBanner=1&ul_noapp=true