I have a couple of suggestions. I presume this is a 24th plastic kit.
It appears glossy, is the interior really like that on the actual car ? I'd tone that down a little. Also try a dark wash based on your main colour or a matt black wash or both. This may bring out a little more detail and show the seperation of the seats to the floor, the rim of the steering wheel to the arms, the glove box etc.
I get the feeling that the paint is quite thick and there appears to be a couple of brush marks across the top of the dash. Its a real art to brush paint large surfaces and this will only come with practise, try thinning down the paint a little and apply a couple of coats rather than just one thicker coat. Use the widest softest brush you have and try to make only one pass.
I'm not quite certain about the right hand trim, it looks a bit rough along here, maybe a mould problem but really you should try and clean that up a little. If the interior was black then it wouldn't show as much but with a light colour and a semi glossy finish then any imperfection like this will show. Likewise the sink holes in the rear parcel shelf. If this can't be seen through the rear window then no problem but if it can be then a little filler before painting will remove such imperfections. I always test fit the body to the chassis to see what can be seen through the windows and from that decide on where the painting attention should be. Foe example if the pedal area can't realy be seen then its no point in spending a lot of time detail painting the pedals.
If you haven't seen it already then check out the article in the May FSM on brush painting.
Keep at it.
Kia ora,
Mark
"Time flies like the wind, fruit flies like bananas"