Published minimums
Big numbers.
Clear class.
Start with the national Solo dimensions, then check the requirements for your region or national event.
SCCA Solo / autocross
at a glance.
Dimensions below refer to the actual character, not the outside panel. Consult the linked official text for the complete provisions.
| Detail | What to plan for |
|---|---|
| Numbers | At least 8 inches high, with a 1¼-inch stroke. |
| Class characters | Uppercase abbreviation; at least 4 inches high and ¾-inch stroke. |
| Relationship | Class height must be 25–75% of numeral height; stroke must also be at least 10% of character height. |
| Position | Both-side body panels. Put class adjacent to the number, using the same typeface and color. |
Source: 2026 Solo Rules · §3.7. The full rule and your event supplements take precedence over this summary.
PLAN THE WHOLE CAR
Every position.
Accounted for.
Measure a clear area at each location before settling on a layout. A door handle, body crease, trim strip, or small front/rear area can change the available footprint.
Position reference: 2026 Solo Rules · §3.7. For magnetic placement limitations, read Magnum’s installation guidance.
Number + class
Number + class
Position list is a planning diagram, not an inspected installation or a scale drawing.
One active identity at a time.
A co-driver digit or Ladies-class L still has to meet the applicable character rules. Keep only the identification for the driver currently competing visible. For national events, check the required SCCA and sponsor decals separately.
Before a production proof
- Check your registered number and any class or run-group identifier.
- Confirm current event requirements and required official decals.
- Measure clear width and height on the actual car.
- Record the finish and check the selected attachment material.
We check the actual characters, stroke widths, positions and supplied fit measurements on the production proof. The on-screen car illustration does not complete those checks.
Your registered class.
Use the code on your accepted entry. These links select artwork labels; they do not determine vehicle eligibility. Regional and supplemental classes can be entered manually.
A few useful answers.
Can a compact panel use smaller characters?
A smaller outside footprint does not relax the national minimum character dimensions. If your usable body-panel area is too small, change the layout or ask the organizer about an appropriate solution before producing the kit. Official reference ↗
Can a magnetic kit work on every car?
No. It needs a suitable magnetic surface and full contact; aluminum, fiberglass, and carbon-fiber panels are not suitable magnetic substrates. Check the actual mounting area and finish. Magnum care and application guidance · Our material guide.
Does this include a guarantee of event compliance?
Our Race Ready service checks number-graphics requirements and provides a correction promise for our documented work. The organizer retains final approval; graphics do not certify vehicle classification, equipment or technical inspection. See our service terms.
Your number, with a plan.
Configure your registered number and class.