Hi jogger1949,
I know what you mean, you don't want anything permanent and as jewel has said if it's your site you are advertising, then you may have to curtail your dark side when you are driving

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SFI, who you can visit yourself or sign up from the link on my site below, introduced a great program a few months ago for members which is called EyeEarn. What you get is a 'T' shirt and a selection of peel off stickers for your car which you can place on the sides or back (or both) and all you have to do is send in a photo of you next to your car wearing your 'T' shirt or just the car if you prefer and every month you will get free affiliates allocated to your downline team. It's a one time only fee so for the sake of $20 you can get free affiliates for evermore and the number you get is dictated by the level you are at in SFI.
I think it's a great idea and well worth the small investment, every month you are just required to answer a very short questionnaire to confirm that you are still advertising the EyeEarn opportunity and you get your free sign ups, it’s worth taking a look.
hope that helps,
Mal.
Work at Home Ideas and Opportunities