Why you should not put your mobile number on the dashboard
Walk any office car park at lunchtime and you will see the same artefact: a torn corner of an envelope, a faded Post-it, a printed card tucked under the wiper. The message is some version of “Sorry if I am blocking you — call me.”
It is polite. It is also a public listing of a personal mobile number, stuck to glass, facing a walkway.
What the note is actually doing
The note tries to solve a real problem. Shared parking is full of temporary blocking. Delivery bays. Parent-and-child spaces used as overflow. Rows so tight that the last car in has to wait for the first car out.
You want a stranger to reach you quickly, without hunting reception, without a scene. A number on the dash is the shortest path you can invent with a pen.
The trouble is that the note cannot tell a blocked colleague from anyone else.
Who else can use that number
Anyone who walks past. A visitor photographing “funny parking notes.” Someone collecting numbers for a resale list. A bored teenager. A person you had a disagreement with in the building.
You do not get to audit the audience. The paper does not expire when you drive home. It does not know that the person scanning it with their eyes is not blocked in at all.
People still do it because the alternative, for years, was worse: no contact, a horn, a nasty note, or a wait that wrecks the school run.
The privacy problem is not theoretical
A mobile number is a key to WhatsApp, to missed-call spam, to “Hi, is this the owner of the silver car?” texts at 11pm. Once it is on a windscreen, you have published it in a place with no access control.
Workplaces feel safe because you recognise the faces. Car parks are not only staff. They are contractors, interviewees, clients, and people using the site as a cut-through.
If you would not print your number on a noticeboard in reception, it does not become a good idea because the paper is smaller and taped to the dashboard.
What “private contact” has to mean
A useful replacement has three jobs:
- A blocked driver can ask for a move in under a minute.
- They do not see your number.
- You do not see theirs.
That rules out a public number, a personal QR that opens WhatsApp, and a sticker that dumps an email address onto a webpage. It also rules out “download our app before you can tell me I am blocking you.” The blocked person will not do that. They will honk.
The pattern that holds up is: a QR on the car opens a page that identifies the vehicle, not the person. The blocked driver confirms the registration. One tap sends a message through a platform that already has your number on file. You get a text. They get a status page. Numbers stay off the glass and off the screen.
What belongs on the sticker instead
The windscreen still needs a human sentence. “Am I blocking you?” is enough. A registration helps the scanner check they have the right car. A QR is the action.
Your name does not belong there. Your company does not need to be there. Your number must not be there.
EMSHI Driver stickers follow that layout on purpose. During launch they are free to print. You add a mobile, a registration, and the look of the car so a scanner can confirm it. After that, the public side is a move request — not a contact card.
If you already have a number on the dash
Take it down. Not next month. The note has already done as much good as it is going to do, and every extra day is extra exposure.
Replace it with something that can notify you without publishing you. If your workplace runs Organization stickers, ask facilities for one rather than inventing a personal card. If you are on your own, print a Driver sticker and put it where the old note used to live.
The goal is the same as the Post-it: when you are the obstruction, a stranger should be able to reach the person who can move the car. The difference is that they should not leave the car park holding your number.