a few more suggestions after playing more:
boxclever is glitchy and that should be noted. It still will not unlock for me even after using the method mentioned. A few folks on TA also have issues with it. Required a reinstall to fix. I will be doing that once I get my last achievement.
u should note that getting three stars doesn't actually mean making no mistakes.. You just need to finish with 5 lives left. Thus is why purchasing the extra lives makes the games much easier. You can make a few mistakes (also in the later levels collecting the extra life pickups helps).
for this reason. I think.it would be much easier to purchase the first two lives first and not worrying about limosine. You wi definitely get it. In fact the last one costs 500k so it will come. I was able to purchase all three lives after getting 3 stars on 100 levels or so. I think you can update the roadmap to just say buy the lives when u get the cash. There is also one level between 91-99 (these levels are all cake) the is just a circle you drive around and there are 32 coins, a great one for boosting cash. Also there are several levels that are just downright undoable. I have also found the levels after 160 to 220 are not harder really. I skip most levels where the sole objectives are trailers. They are the bane of my existence. But yeah there are about 2 cake levels out of every 10.