yeeeeaaahhhh sorta, the trick with playing fretless is you have to really, really, really LISTEN to your notes, fretted basses are very forgiving intonation wise (fret anywhere between two fret and theres your note) on a fretless you have to be BANG ON or it sounds like a cat trying to go to the toilet through a sewn up bum

.
eg, on my fretless (not lined) my D note (A string 5th fret) is actually right on the 'dot', however my D note (D string 12th fret) is more where the c# fret line would be on a fretted.
To get the 'mwah' sound play practically on the neck (around about where the neck meets the body), use a light touch and 'feel' the note (ooo zen) let it swell and then (maybe) use a slight vibrato (because your playing fretless dosent mean you have to slide into and 'wobble' every note)
To get the 'jaco' funk effect play back on the bridge and just use your bridge pup...again USE YOUR EARS.
heres a good exercise:
---2-----7----11------14---
---0-----0-----0-------0---
----------------------------
----------------------------
using your open D string as a 'pedal point/guide tone' play the A, D, F#, A on the G string slowly, take the time over each note to find the correct pitch, a good trick is to listen for 'pulses' generally if the note is sharp or flat you'll hear either a slow or fast pulse, move your finger to the position where you cant hear a pulse (similar to tuning with harmonics)..above all LISTEN.
Hope this helps/makes sense.