I wonder how many IFAs actually invest in the same products they 'flog'....that would be an interesting survey..?
The big question is when/if you need to spend it & could you afford to lose it?
If it's needed to pay off the car in three years time...pay it off now!
If it's 'gambling' money, and you really want a chance of a life changing return from it, don't give it to someone else to gamble - they'll just take a chunk of it for themselves & probably not do much better than a high interest account anyway. Gamble it yourself, but be prepared to lose it.
Personally, & with no advice intended, I opened up a low cost share trading account (with the likes of idealing or Hoodless brennon etc).
Spend a little time reading up about some shares, decide what sector you think will be a grower, & buy some shares in a small company with potential over the next say 5 years. Set a stop loss at whatever you think you can afford to lose (but make it more than 5-10% if in small shares), then walk away & forget about it.
You won't be able to forget about it.
If it comes about that you are fortunate enough to start worrying about capital gains, sell some & stuff the proceeds in an ISA.
I have my 'gambling' funds in OXB & TRP right now (Not advice, just money where mouth is!)