This is how to properly setup your signature to have the ecomodder image with your current mileage in it.
First, open a new tab or window by right clicking on 'User CP' on the top of the screen.
Click on "Edit Signature" on the left side of the screen.
Now, go back to the original tab or window you had open. Click on "EM Garage" and on the next screen click on the "Fuel Log" link of the vehicle whose mileage image you want in your signature.
On the top of the screen, copy the URL of the page.
Go back to your second tab/window and in the signature box type (with no spaces) "[ url=" and then paste the URL behind the equals sign. Then, put a "]" after that. So you'll have something similar to this:
Now, go back to the first tab/window and scroll to the bottom of the page. Right click the signature image you see there and click "Properties".
In the properties window highlight and copy the URL again.
Again, go back to the second tab/window. Immediately after what you had put in before, type (with no spaces) "[ img]" and paste the URL you had copied. Then type "[/img][/url]". Click the "Preview Signature" button to make sure it works. You should have something like this now:
Now, just click "Save Signature" and your all done!