Some sort of sports car or supercar, or even a Tuner-type car.
White and Light blue. (I try not to use that colorscheme as it's sort of.. Ice-themed by now, with Jazzimus being the only/one of the exceptions.)
Two pistols, two guns by her head. (insert 'I'm surprised she's not deaf yet' joke here.)
Before the war, she was a messenger and delivery-woman. She had sided with the Decepticons for unknown reasons, and she is still loyal to them. Elyoria had made her a member of the Decepticon Destroyers, seeing her loyalty and faithfulness. Although Tracer is loyal to them, she would like to see the Decepticons reformed so that its not as harsh or strict it was in the past with the many Warlord-like Decepticon leaders.
Tracer's the predecessor to Sideways as the two are similar and have some similarities, and both were noted as reliable.
Tracer fought Backlash, though Jazz objected to Backlash harming her since she was a mere messenger and not really a warrior. Tracer thanked Jazzimus for his mercy and then a Medidrone healed Tracer. She left, and drove around aimlessly in her altmode until she went into Dashbot territory as one would have to go in their territory to cross the sides. The Dashbots weren't so forgiving and her arm was blown off by one. Both Autobots and Decepticons noted that the '3rd' or '4th' faction was the most annoying faction of all time and didn't want Autobots (or vice-versa) passing in their territory. Tracer survived, though wounded with her right arm blown off, and her left leg sliced off. Cyberwarp saw this and brought her back to their side in a medical tank.
She recovered, though now she shoots Dashbots on sight now.
Behind the Scenes: Edit
She seems similar to Tracer from Overwatch. This isn't on purpose.
I imagine her pistols looking like Starlord's.
Also, there's no Tracer/Chaser duality couple thing going on although their names do sound close and the word 'tracer' could be misheard as 'chaser' and vice-versa (which is one of the many faults of the English language, tbh.)