Thousands of spectators on Wednesday will flock to Valencia's Ricardo Tormo circuit in Cheste.
The main attraction will be the local Spanish hero Fernando Alonso, who delighted the crowd of 15,000 on Tuesday by simply arriving in the paddock at 3.30pm.
On Wednesday, the 28-year-old will make his debut at the wheel of Ferrari's new formula one car, after his teammate Felipe Massa topped the time sheets on the opening two days of the test.
The Spanish sports daily Marca said an impressive 7,000 spectators were already in the grandstands for the opening test day (Monday), boosted no doubt by the presence of the returning Michael Schumacher.
Specialist F1 websites have also been recording impressive visitor figures and resultant server crashes this week, as the extended post-season period and test ban finally ended.