RETURNING TO FREDDY'S:
Start running back towards the fence you've used to get here #1. Press the SPACE key again to leave this area for good. Make sure that you're using a good car before returning to the bar (Jefferson Provincial will do just fine) and that it's not badly damaged (if it is then you should consider paying a visit to the workshop). The reason for that is that you'll soon need a fast and reliable car. Park the vehicle in front of Freddy's and make sure that it is facing north. Enter the bar and head upstairs #2. You'll soon realize that there were some complications and you'll have to sell all the stamps before midnight to earn the cash.
SELLING THE STAMPS AT GAS STATIONS:
Here are a few important things you should know about before starting this new assignment:
1) As soon as you've started this task eight gas stations icons will be added to your map of Empire Bay. You will only have to visit six of them to fully complete this objective. The mission will end after selling the stamps at the sixth gas station and at that point the remaining two won't matter anymore. Don't worry if you don't sell all the stamps by midnight, because you won't have to replay this part of the mission. The only difference is that you won't receive an achievement for selling all the stamps.
2) You can visit the gas stations in any order you want to, however I would recommend that you use the map seen above for the quickest route. It means that you should start with the station marked on the map with 1 and finish with the station marked with 6.
3) You won't have to leave the car after making your way to each station and it's not recommended, because you would only lose precious time. Park your car between gas pumps and the booth and then press the E key to sound the horn.
4) Selling gas stamps won't be possible if you're chased by the police. This means you'll have to avoid starting a police chase at all cost. If a police chase is triggered you should reload the checkpoint, because it'll be very difficult to succeed under such conditions. The main reason is that you won't be allowed to talk to the gas station owner during the chase and losing the cops would take too much time.
5) Police officers will be more tolerate during this entire sequence, so that you won't have to break rapidly each time you've noticed a squad car in your vicinity. Still, you shouldn't take any major risks, because they won't ignore all of your actions.
6) If you've chosen a realistic driving model then winning here will be VERY difficult. I would recommend turning off this mode for the time being. If you're stubborn, you'll have to remember about not making any sudden turns so you won't slide the car and you'll also have to break early to turn where it is needed.
7) Notice that you won't see any red lines on your screen, because the game won't suggest which station should be visited first. Thankfully you can create waypoints yourself by opening the main map of Empire Bay and clicking with left mouse button on a destination of your choice. You can then start following a yellow line seen on the map and on the radar.
Reaching the first gas station (1 on the map) should only take you a five minutes (in the game, not in real life ;-)) #1. Stations two and three (2 and 3 on the map) are kind of hard to get to, because you'll be using narrow roads with a lot of tight turns #2. Apply the gas and brakes wisely, so you won't crash into anything.
You should have at least 30-35 minutes left while selling stamps on the fourth gas station (4 on the map) #1. Once you've sold the objects from your inventory start driving south. You'll be heading towards the southern section of the freeway #2.
Turn right as soon as you've reached the freeway and head west #1, towards the fifth gas station (5 on the map). Don't worry, because even though it's a lot of road to cover you'll be allowed to drive much faster. Watch out only inside the tunnel #2, because you won't be able to avoid some of the cars there.
There's only one more gas station left (6 on the map). I would recommend choosing a larger road built near the river to get there #1, so you won't have to worry about using narrow passageways. Park the car near the station and sell the stamps to finish this part of the mission #2. Depending on the driving model used for this task (normal or realistic) you should have between 5 and 15 minutes left on your clock.
RETURNING TO JOE'S APARTMENT:
You won't have to return to Freddy's for the third time and instead you can proceed directly to Joe's apartment. This is also a good moment to spend some time exploring Empire Bay and visiting different stores. Park you car in the garage when you're ready #1, enter the building and head up to Joe's place. This chapter will end as soon as you decide to go to sleep #2.