You could send the photo to my email.
else
If you have a photo of the actual car, you can right click the jpg, Open with... Microsoft Office, then Picture/Compress Picture. Web size will be small enough to upload.
else
If you Google "1970 Mustang images" you'll see a bunch of pictures. If one looks like what you want, click it (to make it full size), then right click and Copy Image URL. Then you can paste the URL into the posting. Size doesn't matter in this case.