Do you use VCMP's build mode for placing the buses?

No, I figured out the coords myself, but the build mode gives the same coords. I've not tried placing anything else on that spot, but I also found that trying to spawn the Love Fist limo at the location from main.scm it does the same thing as the bus. I'll try spawning something else there and report later during the day.
I spawned some cars around the city halfway through the ground and they appear fine, they're just stuck "sunk" in the tarmac.

Merry Christmas!

And a happy New Year! ;-)

Hi, I'm new here at the forum so I thought I'd start off by contributing something myself.
This code will spawn buses at all the bus stops - you may use it in your OnGameModeInit(), for example.
Please let me know here if I've missed a stop or if you'd like to provide better coordinates :-)
One stop is broken (the one I commented out). I'm not sure why, but if I spawn a bus there it falls through the ground and respawns a little to the side. I tried spawning it a bit higher but that didn't work either (it did not fall through the ground if I spawned it from Z>80). When I spawn a bus at the same coords as it respawns, it falls through the ground again.

The reason for this is simple, I use VC:MP as a simple platform for running races around Vice City with friends. The buses are meant to be an obstacle, but they might work for some other scenario.

Anyway, here's the code:
// West island
// Airport
AddStaticVehicle(167,-1432.89, -780.50,14.79, 90,-1,-1);
// Sunshine Autos
AddStaticVehicle(167,-1019.04, -917.79,14.44, 45,-1,-1);
// Little Havana
AddStaticVehicle(167,-1128.27, -593.15,11.56,268,-1,-1);
AddStaticVehicle(167,-1062.27, -340.08,10.86,268,-1,-1);
AddStaticVehicle(167, -996.25, -513.60,10.86,180,-1,-1);
AddStaticVehicle(167, -908.65, -660.12,11.20,269,-1,-1);
AddStaticVehicle(167, -987.71, -545.34,10.86,  0,-1,-1);
// Downtown
AddStaticVehicle(167, -385.70, 1008.29, 9.99,339,-1,-1);
AddStaticVehicle(167, -295.24, 1284.02,11.69,  0,-1,-1);
AddStaticVehicle(167, -478.18, 1343.06,11.69, 92,-1,-1);
AddStaticVehicle(167, -743.93, 1318.62,11.69, 90,-1,-1);
AddStaticVehicle(167, -874.54, 1350.92,11.38,180,-1,-1);
AddStaticVehicle(167, -869.61, 1074.28,11.00,180,-1,-1);
// East island
// Ocean Beach
AddStaticVehicle(167,  160.57,-1328.51,10.37,160,-1,-1);
AddStaticVehicle(167,  -24.71,-1565.69,10.39, 80,-1,-1);
AddStaticVehicle(167,  -22.11,-1307.33,10.39,  0,-1,-1);
AddStaticVehicle(167,  -77.85, -982.86,10.40 10,-1,-1);
AddStaticVehicle(167,  120.90, -807.78,10.40,325,-1,-1);
AddStaticVehicle(167,  183.71, -487.13,10.99,  0,-1,-1);
AddStaticVehicle(167,  319.78,  -81.48,10.92,  0,-1,-1);
// Vice Point
AddStaticVehicle(167,  428.77,  310.86,11.56,  0,-1,-1);
AddStaticVehicle(167,  472.07,  628.51,11.29,  0,-1,-1);
AddStaticVehicle(167,  228.68,  718.88,10.99,300,-1,-1);
AddStaticVehicle(167,  306.51, 1047.87,13.22, 10,-1,-1);
AddStaticVehicle(167,  449.16, 1273.10,17.37,270,-1,-1);
AddStaticVehicle(167,  498.60, 1022.64,18.07,190,-1,-1);
//AddStaticVehicle(167,  527.11,  628.24,11.00,  0,-1,-1); <-- This is the broken one
// Washington Beach
AddStaticVehicle(167,  516.14,  400.53,10.99,160,-1,-1);
AddStaticVehicle(167,  492.93,   -1.52,10.99,200,-1,-1);
AddStaticVehicle(167,  434.09, -454.09,10.11,180,-1,-1);
AddStaticVehicle(167,  216.84,  -972.83,10.37,170,-1,-1);
Edit history:
2010-12-23 13:26 UTC: Simplified the coordinates.