As far as the Titan goes, you get one for beating all of the Hijacking missions. Here's what I did when I needed money, it's a bit more streamlined.
1. Go to the Carnales Mansion once you acquire it.
2. Retrieve Titan, but don't take it out from the Garage.
3. Shoot two rockets while it's still in there.
4. Wait for it to explode.
5. Immediately retreive another new car from your garage.
6. Walk in there and grab all the money.
7. Repair Titan for $500 and repeat.
The reason for step 5 is so you can avoid having money get stuck inside of the hull of the Titan and avoid the burning wreckage. It works really well once you get the plat RPG because it holds twice as much as the regular luancher and you can reload inside the mansion.
Oh yah, you guys doing the tagging missions are in for a treat. The game loves to make the spray HUD disappear after you initiate a spray(the one that gives you the directions for the tag) so you'll track down a tag and have to guess what the sequence is. It's actually doable by trial and error but it's a colossal pain in the ass. The good thing is that a lot of the time it was just a "A A A A" tag.
In case you guys haven't seen it yet, here's the map I used to track them down and a description of the locations courtesy of the awesome guys at the 360 achievement forums and an inverted version that might be more printer friendly.
The numbers aren't actually that accurate, the actual locations are the pink spray cans besides (or under) them.
KEY-
(R) - Rollers Tag
(V) - Vice Kings Tag
(C) - Carnales Tag
1.-On the side of the white house on the corner (R)
2.-On the tall white wall behind the on of the houses. On the shoreline. (R)
3.-In an ally behind the Technically Legal Club. (R)
4.-On the freeway off ramp right outside of Rim Jobs. (R)
5.-The end apartment building on the second floor. (R)
6.-On the back wall of Rim Jobs. (R)
7.Second floor of the shopping center. On the northern wall. (V)
8.-Second level of the parking garage. (V)
9.-Under a set of stairs in a tall white tower. (V)
10.-In the park over the freeway. Where the overpass meets an ally wall. (V)
11.-Between the Science center and Foriegn Auto. (V)
12.-Top Exterior floor of the science center. (V)
13.-Southeast side of the museum of palentology. (V)
14.-On a freeway wall. (V)
15.-On the back of Stillwater Police Station. (V)
16.-Behind the music store. Take the stairs down behind it. not far from a lightpole (V)
17.-Under the bridge entrance close to the bowling pins (V)
18.-End of the wall in front of Kingdom Come Records (V)
19.-Wall behind the raised walkway north of the fountain courtyard (V)
20.- 2 doors west of the loan office behind a building on a bulkhead. (V)
21.-On apartment wall between apartment and waldo Trade tower. (V)
22.-Inside the aquaduct near the ultradome (R)
23.-Freeway support wall facing the aquaduct (R)
24.-Bay B1 on the ultradome behind a trailer (R)
25.-Walkway through the middle of an old apartmant building. (V)
26.-East of Foriegn Auto, on a brick building (R)
27.-Near the swings in a small playground (V)
28.-Back Parking lot near a wooden fence (V)
29.-Behind a building across the street from the Big Picture Theater. (R)
30.-On the back of the Big Picture Theater (R)
31.-In an alley on the side of a freeway support way. (R)
32.-In the entrance to the train tunnel (V)
33.-On the back of a wharehouse. (R)
34.-On the side of the Chop Shop. (R)
35.-Between the second and third floors on the stairwell. (R)
36.-Wall near the end of the aquaduct. (R)
37.-Wall close to the shoreline (R)
38.-On the side of friendly fire (R)
39.-Outside 2nd floor of On The Ice (R)
40.-Next to the Asain temples. (R)
41.-Under the freeway close to brown baggers (V)
42.-On the side of the **** Cat Strip Club (V)
43.-On the small overpass wall near the strip club. Across from chicken Neds # (V)
44.-Alley across from Psychic Readings sign. (V)
45.-Behind a dumpster on a storage container in a small fenced in area. (V)
46.-Freeway wall by Cheetah Bus Lines (V)
47.-Back of the Train Logistic Building (R)
48.-Corner wall of the green wharehouse (R)
49.-Wharehouse wall between hijacking and insurance fraud. (R)
50.-Durden Logistics Loading bay (R)
51.-Second floor of parking garage near elavators (C)
52.-Fenced in area south of snatch and insurance fraud. Bend in the rd. (C)
53.-Northern most water tower in factory yard. (C)
54.-Near train cars beside the Junkyard. (C)
55.-End of a road, east of the boneyard junkyard. (C)
56.-On a freeway support. (C)
57.-Back of onramps north of Freckle Bitchs billboard. (C)
58.-On a wall in back of J.J. Brown Textile. (C)
59.-Northwest corner of shipyard. Behind a boat haul. (C)
60.-Northwest corner of Durdens Shipping and Storage (C)
61.-End of the middle dock. Jump the railing. (C)
62.-1 block south of plastic surgeon on the side of a brick building. (C)
63.-Behind the shops under the freeway (C)
64.-North side of Durden's (C)
65.-In a court yard across from the no-vin used cars. (C)
66.-Alley between Vinos y Licores and El Jarocho. (C)
67.-Freeway support column near a large pipe. (C)
68.-Back of Forgive & Forget (C)
69.-Under the small bridge. You have to get in the water. (C)
70.-Small wall north of the large crain. (C)
71.-Go between shipping containers to the south side of a warehouse. (C)
72.-Wall near Clayton and Veil Whare on a brick paved loading dock (C)
73.-Last container on the peir. (C)
74.-Side of the road wall. You must jump off the wall into grassy alley. (C)
75.-South side of the first warehouse on the peir. (C)