The bottom of the shell is where most leaks will accumulate even if they start up high. The previous poster was right about checking your awning attachment. Make sure all rivets are tight, clean, and recaulk above awning attachments. Make sure the screws that hold the frame arms on are tight and caulked. Replace vent gaskets (search this site). Windows and then lastly maybe some seams may be the culprit. Mine were a combo of all of the above.
"would you rather have a mansion full of money or a trailer full of love?"