I run through Rahdo's Runthroughs and make right what once went wrong (via annotations)
If I keep taking research points, could I put level 8+ cars and engines on the market and Gran Prix track?
No, 7 ist the highest.
nº 7 is the highest but you can have a car with an engine of 9 if you use the Engineer that gives a +2 to the engine you have put in a car you are selling...
so if you are selling a car with engine 7 and use the engineer +2 token on that car it's considered to have a 9 engine...
and if you have a car with an engine of 7 and I have one with an engine of 6 and that engineer and I use him on that car I will have an engine of 8 and be ahead of you in the engine category for the buyer that wants the best engine