i have a bugaboo frog, bought it almost 6yrs ago and will be using it again when baby no 5 arrives in nov. i have found it to be fab.
i have the orange covers and washed them several times and they always come up looking like new and i also ordered some fleece covers to be made (from someone on ebay) and it didnt cost that much, i had a seat liner and hood made so i can put those on. i did the same for a footmuff/cosytoes thing and can use that as a seat liner as well.
it may be worht looking on ebay as people are often selling of parts and spares on there
otherwise i have got bits that i need, like new front wheels (back ones look as new) but the front ones got quite worn, from john lewis. i got a mattress for the carrycot from there to, not the official bugaboo one, but one that fits, they were happy to let me try it to check
ime john lewis are fab for spare parts etc for the frog, i recently looked at getting the snow wheels you can get for the frog and my local john lewis had them in stock.
i asked recently about ordering new covers etc and they said that would be fine but it may take up to 8 wks depending on stock, but have never had it take that long before.
i truly lOVE my frog it has served us brilliantly and has been WELL used but will still be fine for my next baby and then my sister wants it when i am done with it.