VW Lupo GTi - Recommendation for sporty city car - crjos

A couple of years ago I was looking for a seven seater, and this forum recommended an S-Max, which I've been very happy with. Let's see what you come up with this time!

I'm looking for a small but fun car to use as a complement to the S-Max when I don't need to take out something so big.

It needs to have rear seats but they can be small (as the kids are small, and long journeys would be in the S-Max).

I thought of the Lupo GTi as it seems to be a shrunken version of my old A3, but those cars are 10-15 years old now, and I'm sure that there are more modern equivalents which are out there.

Presumably a small diesel is out of the running due to the high proportion of short journeys we do.

Budget of up to 4k-ish.

Any ideas?