Hidden cars in GTA 4

The cars below are not fixed.
An Ingot VD90R (tuned and I doubt it is available in multiplayer on PS3) is located south of the first city at Hove Beach. You can find it here https://gta.fandom.com/wiki/Ingot
The Sentinel X (unique solo mode) is located in two places: First place, go to the 3rd city and head north on the main road right next to the spawn point of the Sultan RS, second place, go south of the 2nd city in Little Italy, which is the territory of the Rital immigrants.
The modified Intruder is located south of the 2nd city, on the road opposite the bridge connecting the 1st and 2nd city.
The Feroci VIP is located in the same place (it is part of the same clan).
The modified Contender is located north of the 1st city just before the bridge leading to a small town.
The Oracle Xs (in unique solo mode) is located in the same place (same clan).
The Sultan GT is located in the 3rd city just next to a heliport where a Maverick can be found.
The Futo GT is located in Broker (north of the 1st city, the part attached to the bridge), it is on the highway making almost a circle, leading to the Strip Club and an unfinished bridge.
The PMP 600 Charged is also located north of the 3rd city, in the same spots as the Sentinel X.
The Presidente SuperCharged is located in the 3rd city, just before the express bridge on the northeast road circling the city (it is located near the Sultan GT).
But I have a question, do you know why the Ingot in GTA IV on PS3 is not on the road, it can only be found parked, which prevents getting the one that is VD90R???

No, you're going to the airport and you're going on the runway behind a red and white barrier, there will be an NRJ V8 (motorbike).

No, you take a regular Sentinel and stroll around the city, and at some point, you'll encounter a grandma driving a Sentinel X.

Hello, I'm looking for hidden cars too, but I can't find any.
Check out YouTube; there are videos where they have some kind of software that can choose cars and the color of the cars.

It's not a Lamborghini, it's a Pagani Zonda. And to get it, you just have to finish Bernie’s missions; he will give you its location, you go look for it, park it in a private parking space, and restart, and normally there will be some in the city for a little while, just for a moment to pick up another one.
There’s a tuner/upgraded car to the north of the 3rd island, where there’s a private residence with a path that splits into three; I believe it’s at the end of the 2nd path, behind the house, in the tall grass.
Then there are the cheats, but everyone knows them, to obtain the Turismo, the Comet, the Buffalo, the Cognoscenti, the helicopter, the motorboat, and the two motorcycles.
There are no bikes in the game, nor BMXs. There’s a PCJ 600 at the airport, I think.