Your question has an interesting mix of issues. ASAP and 3-4 years doesn't feel like the same thing. ASAP results in bad decisions made in haste. Four years of living very frugally can create a nice down payment on a house.
A car is only an investment for Uber drivers and those who are directly financially benefitting from a car's use. For everyone else, it's a necessary expense.
What I'd focus on is the decision of buying a plot of land. Unless this is a very common way to do it in your country, I don't recommend that order. Having land and then trying to finance the building of a house has far more complexity than most people need in their lives. In my opinion, the better way is to save the 20% down, and buy a new or existing home you can afford.
In the end, spending is a matter of priority. If you truly want to get out in the least time, I'd save every dime I can and start looking for a house that your income can support.