In short: It's a mess.
Perhaps simply search for "Sperre Halterdaten Aargau" or whichever Kanton you're in.
SO: PDF https://www.so.ch/fileadmin/internet...alterdaten.pdf
AI: Write your own letter (use examples from other canton). Has to be sent to Strassenverkehrsamt, Brüggliweg 1, 9050 Appenzell
GL: http://www.gl.ch/xml_1/internet/de/a...d684/f2288.cfm
GR: https://www.gr.ch/DE/institutionen/v...erdaten_DE.pdf
JU:
PDF https://www.jura.ch/Htdocs/Files/v/2...pdf?download=1
NE: http://www.scan-ne.ch/infos/personne...blication.aspx
ZG: Online https://www.zg.ch/behoerden/sicherhe...uskunftssperre
OW: https://www.vsz.ch/fileadmin/files/0...Private_OW.pdf
NW: https://www.vsz.ch/fileadmin/files/0...Private_NW.pdf
SH: https://www.sh.ch/fileadmin/Redaktor...ten_Antrag.pdf
SZ: https://www.sz.ch/public/upload/asse...ndexsperre.pdf
TI: http://www4.ti.ch/fileadmin/DI/Formu...icolazioni.pdf
UR: http://www.ur.ch/de/verwaltung/diens...dienst_id=3568
Can only speak about canton ZH: Blocked it more than a decade ago. Plate was on hold for a certain time. It is still blocked and even the other, additional plate I have is also blocked without any further request.
https://www.zg.ch/behoerden/sicherhe...uskunftssperre
Transferring a car between partners is a common way of getting out of long insurance contracts. Did you do that ?
Happened to me when I lost a plate, and the person who found it phoned me up.
Tom
Mobiles are more often than not, simply not published, particularly employee work mobiles.
Telephone directories used to be twice or three times the thickness they are now.
Thanks all!