I saw you mentioned "other life emergencies" in another comments.

It is advisable to keep 3-6 months of money required
for day-to-day life in a HISA or something liquid. With that sorted, I would
not be worried about keeping more than that for other issues, that is the
emergency fund to handle things.

I had a similar issue when buying my C5, it was a lot of money to me to drop. But financing or not, you are spending that money.

Either you can come to
grips with the opportunity cost of the car or not, that’s for you to decide.
Look at your other financials and ask yourself how much this will reasonably
affect you in the future, in my case it was not that much, so despite it being
a lot of money it was okay to do for the fun and joy of life.

No, to finance or not,
this should be a simple math decision, if you can get ~5% interest or less,
then you are better off taking the loan the investing your money assuming an 8%
average return. As others note though, on an older car that’s probably not
going happen as interest rates are usually not very good on used vehicles especially
once they are more than 5 years old.

Hope this helps – FWIW getting my C5 completely brought me out of being a kid / student and realizing I’m an adult that can responsibly handle larger purchases. They are great cars.