forget the grom get yourself down to halfords and get one of these http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_875559_langId_-1_categoryId_265857 £400 off Pioneer page http://www.pioneer.eu/eur/products/SPH-DA100/print.html
You will need a double din fascia plate mod kit on ebay http://www.ebay.co.uk/itm/270639220846?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
a by pass lead for the lexus Amplifier either this one http://www.ebay.co.uk/itm/Lexus-Amplifier-By-Pass-Lead-Wiring-Harness-PC2-93-4-/250704951293?pt=UK_In_Car_Technology&hash=item3a5f2df7fd
or this one ( depending on the amp fitted in your car ) http://www.ebay.co.uk/itm/PC2-92-4-Lexus-Amplifier-By-Pass-ISO-Stereo-Head-Unit-Harness-Adaptor-Loom-Lead-/180734525470?pt=UK_In_Car_Technology&hash=item2a149e001e
Its fiddly at first,but take your time fitting it I now have over 1500 songs to choose from including video's that are on the iphone,it all works via a pioneer app "AppRadio" from the app store.This touch screen head also works with android phones but you need to purchase a seperate lead from pioneer for that
You also have the facility to fit a reversing camera,this is the one i fitted. http://www.ebay.co.uk/itm/Car-Rear-View-Camera-License-Plate-Night-Vision-Reverse-Parking-Line-Waterproof-/261064513815?pt=UK_In_Car_Technology&hash=item3cc8a85917 I chose this as i did'nt want to put any holes in the body work ,I had to cut the connectors off then re-splice as I used the left hole that the number plate screws use to feed the cables through ( the fascia is stuck on with double sided tape) I did have to get a new number plate as the original Lexus dealer plate was too big
I am really impressed with this unit the onboard amp in the unit is excellent.graphic equaliser and a multitude of settings available including colour,brightness etc for the screen as well as the camera.
If anyone wants more info please feel free to get in touch