Hi Lionel
Go to "User CP" on the left top corner, then "edit avatar" on the left side, then you can upload a pic which will appear on your postings next to your name (like my Kermit).
The maximum size of your custom image is 55 by 55 pixels or 19.5 KB. You can resize a pic eg with
www.irfanview.com or send the pic to me and I'll do it.
If you wanna write something on every post you made, click on "Edit Signature" and you can write down your vehicles.
Greetings from Switzerland
Chris