My question is whats wrong with your car?
A 3.0lt six cylinder engine doesnt struggle...well it shouldnt.
I am in agreement with some, and others not.
We buy cars to commute, enjoy or use as we wish. Now my recommendation - with absolutely no clue on how old you are. Start saving, and buy yourself a toy to play with - if you dont have a large family fund backing you, dont destroy your daily as its firstly a BMW, a new generation one at that - and Parts aint gonna be cheap, specially if you not feeling the control of the slide, because that attracts pavements and so on.
If you neglect some sound advice, this is what I would do:
1)Check tyre pressures.(Soft = more grip, Hard = less grip)
2)Determine if the car has its stock suspension(if its too low or soft, its not going to lose traction too easy - figured this out on my e34, its to low so its not tail happy, until you force it).
3)tyre condition: this shouldnt be a problem for a 3lt...nope, it should shred new rubber as good as old rubber.(consider taking semi's off if its gripping like $hite:roflol

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4)if you having difficulty initiating a Donut, let it roll some, dont start from a stationary position, as your diff ratio may be a bit lot, and better suited for high end, and not acceleration(Im thinking this may be a factor).
PS - the only car that can do a proper unprovoked donut proper...is a M car - very respectable.
Some feedback or vids would give us more insight.