For context, I'm turning 18 soon but passed last year in August. Since then, I've driven a MK6 Golf 1.6 petrol here and there on temporary insurance so I'm not exactly the most experienced yet.

I've managed to get a quote for 2.7k on the Audi and could probably get even cheaper quotes with a few reliable brokers that I know (I can view all policy details before going through with them to make sure they haven't done anything dodgy).

Obviously, a 1.8 turbo isn't a typical choice of engine for a first time driver but I've always had a passion for cars and have read good things about the BAM engine reliability. It's also only 160hp (60 more than the golf whilst also being heavier) so I don't know if the speed difference will be that drastic.

I'm more concerned with non-engine related problems because they're old cars. Although, any engine can go wrong regardless of what people say about reliability, perhaps turbo issues? I'm looking at manuals so I wouldn't have to worry about multitronic gearbox issues.

I'm leaning towards a convertible for the upcoming summer but again, old car, so the roof could be problematic? Also, is a convertible first car a bad shout anyway?

Just looking for a bit of guidance, they're not too expensive (I've seen a few clean, low mileage ones around the 2k-4k region) and the 2.7k quote for insurance is lower than most hatchbacks I've ran quotes on because my area is so high for insurance.

Thoughts? Maybe, I'm just being young and dumb :)

It's electrics that are the biggest problem and parts availability. Make sure all electrical items work on any car you look at and air con, as compressors can be expensive to change. 

Make sure service history is good and there's proof of cambelt and water pump changes and if an auto make sure there's proof of gearbox oil changes. 

Make sure heater is working and air is consistent from all vents because of it's not it could be heater matrix which isn't a cheap job either.