Windshields and your view — California Permit Test
Windshields and your view on the California permit test — 7 rules, each with the reason behind it and a question on it while it is fresh.
The rules
You must not put signs or objects on the front windshield or side rear windows that block your view, and must not hang objects on the mirror.
Anything dangling in front of the glass hides exactly the piece of road a child walks out of.
Not put signs or other objects on the front windshield or side rear windows that block your view.
An object may be affixed within a 7-inch square in the lower corner of the passenger side windshield, or the lower corner of the rear window.
The corner is the one part of the glass a driver is not looking through.
A 7-inch square on the lower corner of the passenger’s side windshield or the lower corner of the rear window.
An object may be affixed within a 5-inch square in the lower corner of the driver’s side window.
The driver’s side is where a mirror check happens, so the allowance there is smaller.
A 5-inch square on the lower corner of the driver’s side window.
An electronic toll payment device may be placed within a 5-inch square in the center uppermost portion of the windshield.
Up against the roof it reads the gantry without sitting in the driver’s line of sight.
A 5-inch square located in the center uppermost portion of your windshield for an electronic toll payment device.
You must not interfere with a funeral procession, which is led by a traffic officer and has the right-of-way, and you can be ticketed for interrupting one.
Cutting into the line separates cars that are trying to stay together to reach one place.
Not interfere with a funeral procession. A funeral procession is led by a traffic officer and has the right-of-way.
Vehicles in a funeral procession carry windshield markers to identify them and have their headlights on.
The markers and the lights are how a driver tells the procession from ordinary traffic.
All vehicles taking part in the procession have windshield markers to identify them and have their headlights on.
You must not operate a vehicle with an illegible license plate, and must not alter a license plate in any way.
A plate nobody can read is a vehicle nobody can identify after a collision.
Not operate a vehicle with an illegible license plate.
On the test
What is the rule about hanging an object from the mirror?
It is not allowed at all. Anything dangling in front of the glass hides exactly the piece of road a child walks out of. California Driver’s Handbook, p.53: “Not put signs or other objects on the front windshield or side rear windows that block your view.”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
- One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
- Free to start: a 10-question test and the first section of cards. No sign-up and no account.
- Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
- Every level up to Prepared — 3 tests passed in a row.
- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against California Driver’s Handbook, published by the California Department of Motor Vehicles, and against the state code itself. Last checked 2026-09-21.
- src/assets/drivers-manuals/CA.pdf (California Driver’s Handbook, DL 600 ENGLISH (REV. 6/2025), retrieved 2026-09-14; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/CA.pages.txt (the pdftotext -layout fixture every citation here was cut against and verified against; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/SOURCES.json, CA entry — the folio offset of 6 and its basis, the three non-law pages, the two sign gallery pages, and the record of why California’s exam shape is this app’s own
- docs/plans/chosen-exam-shapes.md section 5 — the decision that a state publishing neither exam figure ships 40/32 with both disclosed
- docs/plans/how-to-build-laws.md — the rule that the handbook is the syllabus and nothing enters this file without a page in it