Yes you will need the under tray and battery tray/holder and thats it so its the 4 things you need, 1. L/H seat rail, 2. R/H seat rail, 3. plastic under tray, and 4. the metal battery tray then its a case of take your time and do a practice assembly before you start cutting stuff up! If you need anymore help give me a shout on here or pm me i dont mind, good luck! sorry what do you mean by "adaptor"?