More bad news for you, I'm afraid: as the harrier is 4wd, the emissions test is MUCH more expensive - GBP1500 ex VAT at MIRA. The vehicle may also need to be tested up to three times if it is a borderline pass, each time at additional cost. And because there are only a few facilities to do 4wd testing in the country, there's a bit of a wait... :(
It's not specific to Toyota/lexus, but I've written a fairly comprehensive blurb on model reports on the ClubVR4 forums here.
HTH