If you have 1,050 GC and 960,300 R$, you now have the opportunity to do the 10 lapper of le-mans until 11-May!! Edit: Endurance Kings didn't lock after the "win a trip to le-mans" challenge ended 11-May - you can carry on farming!!
If you buy the Porsche 911 RSR (2014) for the sale price of 260GC. Endurance Kings in the Legend Series will also be instantly unlocked. You will need to do a few races with the Porsche 911 RSR (2014) to unlock the Porsche 919 Hybrid for the showcase price of 760GC. The Porsche 919 Hybrid will need 960,300 R$ to upgraded to PR 93.1, you may also need to spend some more gold to upgrade the Porsche 919 Hybrid to PR 94.0, depending on your R$ for the Audi R18 E-tron Quattro (showcase price 3,200,00 R$) and gold for the TOYOTA TS040 Hybrid (showcase 800 GC). If so go for it!
The 10 lapper of le-mans , with the x2 fame manager (pay 1 GC). will give 56,800 fame points, so you can level up and get your gold back! See Fame Chart for your level up points required. Also with your 100% daily bonus and the x2 R$ agent you can get get almost 700,000 R$. If you want to continusly do the pay for the engineer (1GC)
If you have the R$ and GC go for it now :-)
Edit:A Wikia contributor 190.50.201.143
Yep, unlocked Speed Demons and Endurance Kings by pressing Get it Now button. But still got the car with black livery although it was showing a white one.
If you buy it after the showcase, the Get it Now button dissapears and you lose your chance to unlock the series prematurely.
Edit: You can get to the 10 lapper with just the Porsche 919 and 911, you will need to upgrade the 919 to PR94, to get passed 16.2 and 17.1 etc, which are PR 94, the 10 lapper is actually only PR 86. If you can afford the Toyota and Audi you can upgrade the 919 to PR93.1 (only R$ upgrades). If you can't afford them, you need to skip their showcase races so need to do the PR 94 events, I think 3 or 4 GC upgrades - see Porsche 919 Hybrid upgrades with PR, I think you'll need the remaining level 2 GC upgrade and three level 3, about 152 GC. Double check the PR values before you buy them: "These numbers represented are not fully accurate and may differ from the value you see in-game" this is because they change depending on the order you buy the upgrades.