User blog comment:Guy Bukzi Montag/Drop Rates Explained: 5th Anniversary (I)/@comment-34346976-20180910085255/@comment-34918040-20180910112656

@ Audi R8 tyke:

So you have accomplished all quests? Congrats. :-)

Depends on what you want.

The R8 SE box will grant:
 * 1 to 7 blueprints (my real droprate after opening many boxes was at 2.8 BPs per box, not the epected 4 per box, by the way),
 * some credits (perhaps instead, but not very likely),
 * 2 legendary engines (or the i6 multi-engine box, but not very likely).

Or you can buy 5 SLK 55 SE boxes for your :
 * Not very likely that you get at least one blueprint from them (around 41 %, see screenshot),
 * even less credits or tokens,
 * a few rare or motorbike engines (5-8 I guess).

Or if you need BMW M2 SE blueprints to complete your car:
 * 10 Novice bundles will act mostly as a blueprint machine. Your chance of getting 15 blueprints (10 are already guaranteed) should be around 98 %.
 * Very few common engines or common tech are also possible.