$10 matched set of autocross magnetic car numbers (img heavy)
 

Total cost ignoring ink, paper and tape was $9.99 for a 12" x 24" roll of vinyl magnetic sheet from the local Michael's art supply store. They sell printable and sticky-face versions if that's your thing, but I was going for high contrast and completely waterproof.

http://i.imgur.com/8Xd7Paqh.jpg

imgur album containing more pictures

I picked a relatively simple font with a lot of straight lines for easy cutting. Text was just typed into MS word and adjusted for height using the on-screen rulers. These are simple 8" high characters, printed out and then taped in negative (on the back) for contrast.

http://i.imgur.com/PW4gdRjh.jpg

You could probably just trace with a pen, but I found that the change in texture going from cutting vinyl to cutting vinyl + paper let me stay closer to the lines. A straight edge, some curve templates and an xacto knife would probably help here but a good pair of scissors seems to work well enough.

http://i.imgur.com/kxUyVdOh.jpg

When you've been assigned multiple fat characters it's going to have to turn into a game of tetris to keep everything on one sheet.

http://i.imgur.com/WeaT5wth.jpg

I wasn't able to fit 100% of my characters onto the one sheet, but ultimately it shouldn't really be all that noticeable

http://i.imgur.com/6OFSZBUh.jpg

http://i.imgur.com/lAn7H32h.jpg

Courtesy tabs (tape partially folded over onto itself) greatly simplify trying to line up all of the numbers on the side of your car.

http://i.imgur.com/MQsotS5h.jpg

Lessons learned:

1. Courtesy tabs can probably be fully behind the characters to give a clean look, as long as you give your finger an edge to catch onto
2. Put any such tabs on the trailing edge of your numbers so they don't get peeled off by the wind

http://i.imgur.com/Ej8oZ92h.jpg

I would just like to warn anyone thinking of doing this

cars get dirty, the stickers get dirty, esp if you're putting them on in a hurry or after a long drive.

make sure that the surface is clean and the numbers are clean, otherwise there is a chance to introduce micro scratches to your clearcoat/paint

it's ridiculous how easily these numbers/decals can get all dusted up. Esp after a rain day etc.

that's part of the reason why I'm willing to put up with the ugly tabs on the edges - I probably didn't emphasize this enough but you do not want to be dragging the magnets across your door while lining them up. lift and reapply.

Thanks for the idea bud. I picked up that 1'x2' roll of magnetic adhesive vinyl. I cut it into two 8.5"x11" pieces (there was a spare ~7" wide piece). Then I made up some numbers in photoshop, printed them to another piece of paper, adhered it to the mag-vinyl, then cut out the numbers. Done one side so far. Takes a while, but I think it looks nice. Dunno how long it'll last, but maybe next time I'll do it out of some heartier glossy paper. Anyhow, here's some pics.

No offense to OP, but Why do this? What benefits do these bring? =) I'm just wondering because I don't get it. If you can indulge my curiosity that would be nice.

For those that take there cars to autocross, you get assigned a number that you need to put on your car when you sign in. I'm not sure if there are other reasons.

Ahh thanks. Why not just use painter's tape for temp and not risk screwing up the paint?

Sent from my PG86100

Because these would take less effort each time, are very clear and they look great as well.

Good ting to do if you go to autocross regularly

Understood -- Just wanted to find out why -- thanks guys.

Great DIY!

To give others an idea of the cost-savings of doing this yourself, my autocross numbers that I ordered from autocrossnumbers.com cost me $87 for the set!

NEVER AGAIN!

Scott

Could you paint the magnetic vinyl? Doesn't seem like white paper will hold up very well.

I imagine you could paint it with the same sandpaper/deglosser/primer/enamel type setup used for painting vinyl flooring, but a better option might be to spend the extra few dollars to order it pre colored online.

also, if you want to be really fancy you could get a sign shop to cut it with a laser cutter.

After using magnetics for autox for about 10 years, I have found that the Michael's magnetic material will get 'roughed up' and tend to fly off cars when aged a few years. I have also used magnetic material I scored from a sign shop for about the same pricing as nationwide Michaels, but with much greater quality, about twice as thick, and these decals/numbers have never come off.

If a person is going to autox any more than once a year, one should leave the blue tape for novices/first timers. This was the first 'mod' I did to my car when I started autocrossing. Besides the pics look better with true numbers, unless one is uber-meticulous, and at that point it may be better time-wise to create semi-permanent numbers from magnets

+1 to cleaning up both car surface and magnetic surface before sticking them on. Just sitting on the shelf, the magnets seem to attract (pun intended) all sorts of dust and debris.

Eric G

I completely agree. The Michaels magnetic material is WAY too thin. It lasted 2 events before they were flying off... I sourced mine from a custom sign/mom-and-pop art store. Their material is at least twice as thick as the Michaels material and still sticks every time.