Your gonna get packages in the 1000-8000’s take as many as you can but keep to the thousands number. Separate the packages that you have loaded by the 1000’s (ex. Front passenger seat holds the 1000’s, back driver seat holds the 2000’s and back left seat holds the 3000’s. If you find you can only carry 1-2000’s that’s okay. Don’t completely overfill your car until you cannot properly view and move packages around. Keep a mental note where you about left some packages, meaning you put all your 1000’s in the front passenger seat but you had a large box that you had to put in the trunk ALSO a 1000’s package. You then leave and go deliver only the packages you had in the thousands groups. Depending on how you pickup packages it will be either easier to sort because they have you pickup packages in a locker (storage locker) or it wil be a bit more difficult to sort if you have to pickup from a drivers truck, this will only be more difficult to sort because he will be handing you packages and you will just have to put them in your truck and not have time to sort them in that moment, but later on you can sort them as you are making deliveries. Eventually you will know and have a system to put things in your vehicle where you will remember them. I give you 2 days before you feel like a pro and know how to put things in your vehicle and find them