How do I unlock the final missions in GTA: Vice City?

So I've never actually played Vice City through and I always seem to get stuck at around this particular point...

Due to the sandbox nature of the game, I thought I'd ask for a hand here and see if we can't figure out what I'm supposed to do next, so...

What I've already done

• Completed the Vercetti Estate missions (I have the $5000 passive income)
• Completed the Cortez missions (he's left)
• Completed the Love Fist missions that I have (last one was the bomb in the limo)
• Completed the Cuban/Hatian missions (killed the Cubans from the rooftop and bombed the Hatian facility)

There's nothing else on the map and I figure I probably need to purchase some extra properties to continue. I'll explore this idea going forward...

So far I have purchased

• Pole Position
• "Ice Cream" company
• Some safe houses dotted around

Clearly not the best way to spend my $$ and probably why I don't even have 100k yet, but nothing I can do about that now.

Does anyone have any suggestions what I can do next?

Solution 1:

At this point there are multiple businesses which you can purchase. Each will unlock a short mission chain, minigame or activity which, when completed, earns you money per day.

Completing enough of these (which must include the printing press and The Malibu) will unlock the final missions.

Here's a list of the properties which make money:

• The boatyard- Costs $10k, produces $2k/day after completing a series of speedboat time trials.
• The ice cream factory- Costs $20k, produces $3k/day after earning enough money from the drug dealing minigame.
• The Pole Position club- Costs $30k, produces $4k/day after spending $300 in the back room.
• Kaufman Cabs- Costs 40k, produces 5k/day after completing the mission chain.
• Car showroom- Costs 50k, produces 6k/day after acquiring 4 lists of cars.
• Film studio- Costs 60k, produces 7k/day after completing the mission chain.
• Print works- Costs 70k, produces 8k/day after completing the mission chain and is required to unlock the final missions.
• The Malibu- Costs 120k, produces 10k/day after completing the mission chain and is also required for the final missions.