Objectives: Recover the Swoop Bike Accelerator
Within moments of your arrival, the garage head and a couple of bodyguards will arrive out of a door to the north. They won't see you right away, so take the opportunity to repair one of the nearby droids to help you if you have extra parts, or just start blasting. After they go down, head to the west, where those enemies were walking from, to find the garage head's office, which contains the garage head's key card and a security terminal, which emulates most of the commands of the terminal in the main facility upstairs.
Head back to the main garage and take the southern passage. Head west at the branch to find a couple of smaller garage facilities, one of which contains a workbench. This is the perfect time to upgrade your weaponry; you should've been finding plenty of items around the Vulkar Base. If anyone in your party uses blaster rifles, you should max out Zaalbar's Bowcaster; if you pump it full of upgrades, you can transform it into a +3 attack bonus beast that deals out 3-12 damage, with a critical range of 17-20.
The eastern rooms here contain one Kandon Ark, a Brejik subcommander with an interesting offer. He says that if you kill Gadon Thek, he'll pay you 500 credits and give you Bastila, without requiring you to win the swoop race. (Note that this is a trick: even if you do kill Gadon, you’ll still be forced into the swoop race. The assassination mission will net you a lot of loot from the Hidden Bek base, though.) This is one of the first critical choices for Dark side candidates, and is a perfectly viable alternative to slaughtering Kandon and his bodyguards. If you decide to be virtuous (for now), kill Kandon and his cohorts. Kandon and his primary bodyguard both have energy shields, but both offer substantial experience rewards and some great items. If you're having trouble with them, cycle through your characters and have them all offload your stockpile of grenades on Kandon's Twi'lek bodyguard; both he and she should fall after five or six of your little friends go off.
Yet again, grenades make a hard fight easy.
If on the other hand, you want to take out Thek, head back to the Bek base, speak to Zaerdra, and start knocking heads. With the key that Kandon gave you, you'll be able to bypass all of the security doors that stymied your progress before. When you reach the second floor, gear up for a fight; Gadon may be blind, but he can still kick some ass when his back is up against the wall.
Before you leave the garage, though, you might want to try your hand at a tough battle in the loading bay. You may need to use the security terminal in the garage head's office to unlock the door; the garage head's key pass doesn't seem to work on it. Once inside, you'll face off against a single Vulkar patrol droid, which has some kind of freezing effect that can stun your party members for a short time. It has 24 defense, which will make it quite difficult for your characters to actually hit it, and deals quite a bit of damage. You may want to let one of your characters get up close, then throw a few ion grenades into the mix to hopefully knock most of its life away. The fight is worth it, though; one of the nearby locked footlockers contains 2,000 credits, plasma grenades, and other items.
Once you reach the Bek base, save your game and talk to Gadon to begin the sequence of events that leads up to the swoop race. If you decided to kill Gadon, then do so and return to the Vulkar base to begin the race.