Purple is rare as a prominent colour for an Autobot toy, as it seemed to be reserved for "evil" toys (almost every 1988 Decepticon had purple on it somewhere)... but we do have a few contenders.

Grotusque
Trizer
Rodney
AM Skyfall
Euro Deluge
G2 Gobots Ironhide
BW Cybershark
RID Skid-Z
Armada Cheetor
2003 Universe (Fuzor) Silverbolt
JP SCF Alpha Trion
2002 Gorilla-Bot
2003 Beast-Bot II (cheetah)
2003 Buzzer-Bot (wasp)
2004 Beast-Bot (gorilla)
2004 Buzzer-Bot (motorcycle)
2005 Beast-Bot (dinosaur)
2005 Racer-Bot Beta (hotrod)
2005 Racer-Bot Beta Roadster (hotrod)
Universe Minicon-class Windrazor (packaging notes it as Autobot)
Universe Minicon-class Makeshift (packaging notes it as Autobot)
JP Beast Wars Returns (BM) Silverbolt
2007 Arcee
2007 Battle Damaged Arcee
BotCon 2007 Alpha Trion
2010 Autobot Alliance Twins (darker redeco, so looks purplish)
Human Alliance Elita-1
Kreon Alpha Trion
GO! Sensuimaru
One of the Kabaya Aerialbots