If you've got the tapatalk app on your phone, you can upload pics on your phone through the app.
One thing to be aware of though is that it will also upload all EXIF data (including GPS location). This means somebody could figure out your home location and where the car is for example. Depends if that bothers you or not. If I upload any pics taken at my home address from my phone, I use a separate app that deletes EXIF data ("Metadata Cut"). The only reason this came up was because I'm also on the RS246 forum, where a number of members had cars stolen and it seemed the thieves seemed to know where to find the cars.
I use flickr for image hosting most of my pics. Only downside with flickr is that you have to be on a PC/laptop to get the image link for the forums. Annoying.